---
_id: '64864'
abstract:
- lang: eng
  text: Probing novel properties, arising from twisted interfaces, has traditionally
    relied on the stacking of exfoliated two-dimensional materials and the spontaneous
    formation of van der Waals bonds. So far, investigations involving intimate covalent
    or ionic bonds have not been a focus. Yet, we show here that an established technique,
    involving thermocompressional wafer bonding, works well for creating twisted non-van
    der Waals interfaces. We have successfully bonded z-cut lithium niobate single
    crystals to create ferroelectric oxide interfaces with strong polar discontinuities
    and have mapped the associated emergent interfacial conductivity. In some instances,
    a dramatic change in microstructure occurs, involving local dipolar switching.
    A twist-induced collapse in the capability of the system to effec8tively screen
    interfacial bound charge is implied. Importantly, this only occurs around specific
    moiré twist angles with sparse coincident lattices and associated short-range
    aperiodicity. In quasicrystals, aperiodicity is known to induce pseudo-bandgaps
    and we suspect a similar phenomenon here.
article_number: '1842'
article_type: original
author:
- first_name: Andrew
  full_name: Rogers, Andrew
  last_name: Rogers
- first_name: Kristina
  full_name: Holsgrove, Kristina
  last_name: Holsgrove
- first_name: Nils A.
  full_name: Schäfer, Nils A.
  last_name: Schäfer
- first_name: Boris
  full_name: Koppitz, Boris
  last_name: Koppitz
- first_name: Conor J.
  full_name: McCluskey, Conor J.
  last_name: McCluskey
- first_name: Shivani
  full_name: Yedama, Shivani
  last_name: Yedama
- first_name: Ronan
  full_name: Lynch, Ronan
  last_name: Lynch
- first_name: Keelan
  full_name: Sloan, Keelan
  last_name: Sloan
- first_name: Barry
  full_name: Porter, Barry
  last_name: Porter
- first_name: Adam
  full_name: Sykes, Adam
  last_name: Sykes
- first_name: Alex
  full_name: Catalan Daniels, Alex
  last_name: Catalan Daniels
- first_name: Romualdo S.
  full_name: Silva, Romualdo S.
  last_name: Silva
- first_name: Flavio Y.
  full_name: Bruno, Flavio Y.
  last_name: Bruno
- first_name: Sam D.
  full_name: Seddon, Sam D.
  last_name: Seddon
- first_name: Haidong
  full_name: Lu, Haidong
  last_name: Lu
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Christa
  full_name: Fink, Christa
  last_name: Fink
- first_name: Philipp
  full_name: Fahler-Muenzer, Philipp
  last_name: Fahler-Muenzer
- first_name: Sarah
  full_name: Fearn, Sarah
  last_name: Fearn
- first_name: Sandrine E. M.
  full_name: Heutz, Sandrine E. M.
  last_name: Heutz
- first_name: Marios
  full_name: Hadjimichael, Marios
  last_name: Hadjimichael
- first_name: Quentin M.
  full_name: Ramasse, Quentin M.
  last_name: Ramasse
- first_name: Marin
  full_name: Alexe, Marin
  last_name: Alexe
- first_name: Amit
  full_name: Kumar, Amit
  last_name: Kumar
- first_name: Raymond G. P.
  full_name: McQuaid, Raymond G. P.
  last_name: McQuaid
- first_name: Alexei
  full_name: Gruverman, Alexei
  last_name: Gruverman
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
- first_name: J. Marty
  full_name: Gregg, J. Marty
  last_name: Gregg
citation:
  ama: Rogers A, Holsgrove K, Schäfer NA, et al. Polar discontinuities, emergent conductivity,
    and critical twist-angle-dependent behaviour at wafer-bonded ferroelectric interfaces.
    <i>Nature Communications</i>. 2026;17(1). doi:<a href="https://doi.org/10.1038/s41467-026-68553-7">10.1038/s41467-026-68553-7</a>
  apa: Rogers, A., Holsgrove, K., Schäfer, N. A., Koppitz, B., McCluskey, C. J., Yedama,
    S., Lynch, R., Sloan, K., Porter, B., Sykes, A., Catalan Daniels, A., Silva, R.
    S., Bruno, F. Y., Seddon, S. D., Lu, H., Rüsing, M., Fink, C., Fahler-Muenzer,
    P., Fearn, S., … Gregg, J. M. (2026). Polar discontinuities, emergent conductivity,
    and critical twist-angle-dependent behaviour at wafer-bonded ferroelectric interfaces.
    <i>Nature Communications</i>, <i>17</i>(1), Article 1842. <a href="https://doi.org/10.1038/s41467-026-68553-7">https://doi.org/10.1038/s41467-026-68553-7</a>
  bibtex: '@article{Rogers_Holsgrove_Schäfer_Koppitz_McCluskey_Yedama_Lynch_Sloan_Porter_Sykes_et
    al._2026, title={Polar discontinuities, emergent conductivity, and critical twist-angle-dependent
    behaviour at wafer-bonded ferroelectric interfaces}, volume={17}, DOI={<a href="https://doi.org/10.1038/s41467-026-68553-7">10.1038/s41467-026-68553-7</a>},
    number={11842}, journal={Nature Communications}, publisher={Springer Science and
    Business Media LLC}, author={Rogers, Andrew and Holsgrove, Kristina and Schäfer,
    Nils A. and Koppitz, Boris and McCluskey, Conor J. and Yedama, Shivani and Lynch,
    Ronan and Sloan, Keelan and Porter, Barry and Sykes, Adam and et al.}, year={2026}
    }'
  chicago: Rogers, Andrew, Kristina Holsgrove, Nils A. Schäfer, Boris Koppitz, Conor
    J. McCluskey, Shivani Yedama, Ronan Lynch, et al. “Polar Discontinuities, Emergent
    Conductivity, and Critical Twist-Angle-Dependent Behaviour at Wafer-Bonded Ferroelectric
    Interfaces.” <i>Nature Communications</i> 17, no. 1 (2026). <a href="https://doi.org/10.1038/s41467-026-68553-7">https://doi.org/10.1038/s41467-026-68553-7</a>.
  ieee: 'A. Rogers <i>et al.</i>, “Polar discontinuities, emergent conductivity, and
    critical twist-angle-dependent behaviour at wafer-bonded ferroelectric interfaces,”
    <i>Nature Communications</i>, vol. 17, no. 1, Art. no. 1842, 2026, doi: <a href="https://doi.org/10.1038/s41467-026-68553-7">10.1038/s41467-026-68553-7</a>.'
  mla: Rogers, Andrew, et al. “Polar Discontinuities, Emergent Conductivity, and Critical
    Twist-Angle-Dependent Behaviour at Wafer-Bonded Ferroelectric Interfaces.” <i>Nature
    Communications</i>, vol. 17, no. 1, 1842, Springer Science and Business Media
    LLC, 2026, doi:<a href="https://doi.org/10.1038/s41467-026-68553-7">10.1038/s41467-026-68553-7</a>.
  short: A. Rogers, K. Holsgrove, N.A. Schäfer, B. Koppitz, C.J. McCluskey, S. Yedama,
    R. Lynch, K. Sloan, B. Porter, A. Sykes, A. Catalan Daniels, R.S. Silva, F.Y.
    Bruno, S.D. Seddon, H. Lu, M. Rüsing, C. Fink, P. Fahler-Muenzer, S. Fearn, S.E.M.
    Heutz, M. Hadjimichael, Q.M. Ramasse, M. Alexe, A. Kumar, R.G.P. McQuaid, A. Gruverman,
    S. Sanna, L.M. Eng, J.M. Gregg, Nature Communications 17 (2026).
date_created: 2026-03-08T09:20:13Z
date_updated: 2026-03-08T09:22:25Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1038/s41467-026-68553-7
intvolume: '        17'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.nature.com/articles/s41467-026-68553-7
oa: '1'
publication: Nature Communications
publication_identifier:
  issn:
  - 2041-1723
publication_status: published
publisher: Springer Science and Business Media LLC
quality_controlled: '1'
status: public
title: Polar discontinuities, emergent conductivity, and critical twist-angle-dependent
  behaviour at wafer-bonded ferroelectric interfaces
type: journal_article
user_id: '22501'
volume: 17
year: '2026'
...
---
_id: '66939'
abstract:
- lang: eng
  text: "Many quantum optical applications in spectroscopy, communication and signal
    analysis rely on spectrally-engineered nonlinear optical interactions to target
    specific wavelengths or bandwidth. Here, in an established material platform like
    lithium niobate the achievable wavelength and bandwidth combinations are usually
    limited by the material’s dispersion and its birefringence. In this regard, mixed
    crystals of lithium niobate tantalate (LNT) promise a novel material platform,
    because they allow tuning the birefringence, which is central for type II phase
    matching devices. Crucially, LNT offers crystal  compositions without any birefringence,
    which still retain their second-order optical nonlinearity. Despite recent progress
    in the growth and fabrication of LNT, so far no works have investigated the unique
    properties of LNT for use in electro-optics, nonlinear or quantum optics. In this
    study, we explore nonlinear optical devices based on LNT for broad- and narrowband
    nonlinear optical interactions based on recently measured Sellmeier coefficients.
    Most interestingly, we find that compositions without birefringence allow the
    design of broadband, degenerate type II phase matching sources spanning the whole
    near- to mid-infrared range by only changing the poling period and pump wavelength.
    Such devices are not easily realizable in pure lithium niobate or lithium tantalate.
    This could potentially allow for\tmore flexible light sources and nonlinear devices
    in quantum metrology, quantum spectroscopy and quantum communication."
article_number: '2668'
article_type: original
author:
- first_name: Franz
  full_name: Roeder, Franz
  id: '88149'
  last_name: Roeder
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Tobias
  full_name: Hehemann, Tobias
  last_name: Hehemann
- first_name: Abira
  full_name: Gnanavel, Abira
  id: '81424'
  last_name: Gnanavel
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Benjamin
  full_name: Brecht, Benjamin
  id: '27150'
  last_name: Brecht
  orcid: '0000-0003-4140-0556 '
- first_name: Mirco
  full_name: Imlau, Mirco
  last_name: Imlau
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
citation:
  ama: 'Roeder F, Rüsing M, Hehemann T, et al. Lithium niobate tantalate mixed crystals:
    a versatile platform for nonlinear quantum processes. <i>Optical Materials Express</i>.
    2026;16(8). doi:<a href="https://doi.org/10.1364/ome.592892">10.1364/ome.592892</a>'
  apa: 'Roeder, F., Rüsing, M., Hehemann, T., Gnanavel, A., Eigner, C., Brecht, B.,
    Imlau, M., &#38; Silberhorn, C. (2026). Lithium niobate tantalate mixed crystals:
    a versatile platform for nonlinear quantum processes. <i>Optical Materials Express</i>,
    <i>16</i>(8), Article 2668. <a href="https://doi.org/10.1364/ome.592892">https://doi.org/10.1364/ome.592892</a>'
  bibtex: '@article{Roeder_Rüsing_Hehemann_Gnanavel_Eigner_Brecht_Imlau_Silberhorn_2026,
    title={Lithium niobate tantalate mixed crystals: a versatile platform for nonlinear
    quantum processes}, volume={16}, DOI={<a href="https://doi.org/10.1364/ome.592892">10.1364/ome.592892</a>},
    number={82668}, journal={Optical Materials Express}, publisher={Optica Publishing
    Group}, author={Roeder, Franz and Rüsing, Michael and Hehemann, Tobias and Gnanavel,
    Abira and Eigner, Christof and Brecht, Benjamin and Imlau, Mirco and Silberhorn,
    Christine}, year={2026} }'
  chicago: 'Roeder, Franz, Michael Rüsing, Tobias Hehemann, Abira Gnanavel, Christof
    Eigner, Benjamin Brecht, Mirco Imlau, and Christine Silberhorn. “Lithium Niobate
    Tantalate Mixed Crystals: A Versatile Platform for Nonlinear Quantum Processes.”
    <i>Optical Materials Express</i> 16, no. 8 (2026). <a href="https://doi.org/10.1364/ome.592892">https://doi.org/10.1364/ome.592892</a>.'
  ieee: 'F. Roeder <i>et al.</i>, “Lithium niobate tantalate mixed crystals: a versatile
    platform for nonlinear quantum processes,” <i>Optical Materials Express</i>, vol.
    16, no. 8, Art. no. 2668, 2026, doi: <a href="https://doi.org/10.1364/ome.592892">10.1364/ome.592892</a>.'
  mla: 'Roeder, Franz, et al. “Lithium Niobate Tantalate Mixed Crystals: A Versatile
    Platform for Nonlinear Quantum Processes.” <i>Optical Materials Express</i>, vol.
    16, no. 8, 2668, Optica Publishing Group, 2026, doi:<a href="https://doi.org/10.1364/ome.592892">10.1364/ome.592892</a>.'
  short: F. Roeder, M. Rüsing, T. Hehemann, A. Gnanavel, C. Eigner, B. Brecht, M.
    Imlau, C. Silberhorn, Optical Materials Express 16 (2026).
date_created: 2026-09-02T11:53:45Z
date_updated: 2026-09-02T13:35:22Z
department:
- _id: '288'
- _id: '623'
- _id: '15'
doi: 10.1364/ome.592892
funded_apc: '1'
intvolume: '        16'
issue: '8'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1364/OME.592892
oa: '1'
publication: Optical Materials Express
publication_identifier:
  issn:
  - 2159-3930
publication_status: published
publisher: Optica Publishing Group
quality_controlled: '1'
status: public
title: 'Lithium niobate tantalate mixed crystals: a versatile platform for nonlinear
  quantum processes'
type: journal_article
user_id: '22501'
volume: 16
year: '2026'
...
---
_id: '66942'
abstract:
- lang: eng
  text: Raman imaging, based on incoherent spontaneous Raman scattering (SR) or coherent
    techniques such as broadband coherent anti-Stokes Raman spectroscopy (BCARS),
    is a powerful tool for visualizing local lattice distortions. It can thus be employed,
    e.g., to identify and visualize ferroelectric (FE) domain walls (DWs). While SR-based
    DW imaging relies on small changes in the intensity or position of Raman peaks
    at the DW, BCARS measurements may detect DW signatures with a drastically increased
    contrast and orders of magnitude faster imaging speed. However, while SR-based
    contrasts can be predicted from existing models, the increased DW contrasts in
    BCARS remain poorly understood. In this work, we develop a first-principles approach
    for the simulation of CARS spectra to investigate the origin of this BCARS signal
    contrast at periodically poled stoichiometric lithium niobate (sPPLN) DWs. Combining
    these atomistic simulations with strain modeling allows us to explore how strain
    affects the CARS signal generation at FE DWs. We then apply polarization-sensitive
    BCARS to image sPPLN DWs for different polarization configurations. Our results
    reveal additional Raman peaks specific to the DWs across all investigated polarization
    combinations, yielding a strong DW-to-bulk contrast that enables in situ identification
    and localization of DWs in two-dimensional BCARS maps. This study demonstrates
    the practical utility of polarization-sensitive BCARS for fast DW imaging and
    provides fundamental insights into the BCARS contrast mechanism in FE materials,
    both in strained regions and in the unstrained bulk.
article_number: '034104'
article_type: original
author:
- first_name: Robin
  full_name: Buschbeck, Robin
  last_name: Buschbeck
- first_name: Mike N.
  full_name: Pionteck, Mike N.
  last_name: Pionteck
- first_name: Naomi
  full_name: Herrmann, Naomi
  last_name: Herrmann
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Susanne C.
  full_name: Kehr, Susanne C.
  last_name: Kehr
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: 'Buschbeck R, Pionteck MN, Herrmann N, et al. Ab initio modeling and experimental
    analysis of contrast in broadband coherent anti-Stokes Raman spectroscopy: A case
    study on ferroelectric domain walls. <i>Physical Review B</i>. 2026;114(3). doi:<a
    href="https://doi.org/10.1103/m1xq-rlft">10.1103/m1xq-rlft</a>'
  apa: 'Buschbeck, R., Pionteck, M. N., Herrmann, N., Rüsing, M., Kehr, S. C., Sanna,
    S., &#38; Eng, L. M. (2026). Ab initio modeling and experimental analysis of contrast
    in broadband coherent anti-Stokes Raman spectroscopy: A case study on ferroelectric
    domain walls. <i>Physical Review B</i>, <i>114</i>(3), Article 034104. <a href="https://doi.org/10.1103/m1xq-rlft">https://doi.org/10.1103/m1xq-rlft</a>'
  bibtex: '@article{Buschbeck_Pionteck_Herrmann_Rüsing_Kehr_Sanna_Eng_2026, title={Ab
    initio modeling and experimental analysis of contrast in broadband coherent anti-Stokes
    Raman spectroscopy: A case study on ferroelectric domain walls}, volume={114},
    DOI={<a href="https://doi.org/10.1103/m1xq-rlft">10.1103/m1xq-rlft</a>}, number={3034104},
    journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Buschbeck,
    Robin and Pionteck, Mike N. and Herrmann, Naomi and Rüsing, Michael and Kehr,
    Susanne C. and Sanna, Simone and Eng, Lukas M.}, year={2026} }'
  chicago: 'Buschbeck, Robin, Mike N. Pionteck, Naomi Herrmann, Michael Rüsing, Susanne
    C. Kehr, Simone Sanna, and Lukas M. Eng. “Ab Initio Modeling and Experimental
    Analysis of Contrast in Broadband Coherent Anti-Stokes Raman Spectroscopy: A Case
    Study on Ferroelectric Domain Walls.” <i>Physical Review B</i> 114, no. 3 (2026).
    <a href="https://doi.org/10.1103/m1xq-rlft">https://doi.org/10.1103/m1xq-rlft</a>.'
  ieee: 'R. Buschbeck <i>et al.</i>, “Ab initio modeling and experimental analysis
    of contrast in broadband coherent anti-Stokes Raman spectroscopy: A case study
    on ferroelectric domain walls,” <i>Physical Review B</i>, vol. 114, no. 3, Art.
    no. 034104, 2026, doi: <a href="https://doi.org/10.1103/m1xq-rlft">10.1103/m1xq-rlft</a>.'
  mla: 'Buschbeck, Robin, et al. “Ab Initio Modeling and Experimental Analysis of
    Contrast in Broadband Coherent Anti-Stokes Raman Spectroscopy: A Case Study on
    Ferroelectric Domain Walls.” <i>Physical Review B</i>, vol. 114, no. 3, 034104,
    American Physical Society (APS), 2026, doi:<a href="https://doi.org/10.1103/m1xq-rlft">10.1103/m1xq-rlft</a>.'
  short: R. Buschbeck, M.N. Pionteck, N. Herrmann, M. Rüsing, S.C. Kehr, S. Sanna,
    L.M. Eng, Physical Review B 114 (2026).
date_created: 2026-09-02T12:04:02Z
date_updated: 2026-09-02T12:06:24Z
department:
- _id: '15'
- _id: '288'
- _id: '623'
doi: 10.1103/m1xq-rlft
intvolume: '       114'
issue: '3'
language:
- iso: eng
publication: Physical Review B
publication_identifier:
  issn:
  - 2469-9950
  - 2469-9969
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: 'Ab initio modeling and experimental analysis of contrast in broadband coherent
  anti-Stokes Raman spectroscopy: A case study on ferroelectric domain walls'
type: journal_article
user_id: '22501'
volume: 114
year: '2026'
...
---
_id: '66941'
abstract:
- lang: eng
  text: Understanding and controlling the optical properties of lithium niobate tantalate
    solid solutions (LiNb1−xTaxO3, 0 ≤ x ≤ 1) is essential for their use in integrated
    quantum and nonlinear photonics. This material system allows for composition-dependent
    tuning of key optical parameters such as refractive indices and birefringence.
    While lithium niobate (LiNbO3, x = 0) and lithium tantalate (LiTaO3, x = 1) are
    well characterized, reliable dispersion data for intermediate compositions remain
    scarce, limiting accurate modeling and refractive index engineering. Here, we
    address this gap by experimentally determining the ordinary and extraordinary
    refractive indices of LiNb1−xTaxO3 over the spectral range of 405 − 1550 nm using
    an interferometric technique. As a result, composition-dependent refractive index
    dispersion and Sellmeier coefficients are derived and discussed in relation to
    previous studies and structural aspects. In particular, a monotonic decrease of
    the ordinary refractive index with increasing Tantalum concentration is observed.
    The present Sellmeier coefficients further allow discussion of zero birefringence
    dispersion and its composition dependence in lithium niobate tantalate.
article_number: '2069'
article_type: original
author:
- first_name: Tobias
  full_name: Hehemann, Tobias
  last_name: Hehemann
- first_name: Niklas
  full_name: Dömer, Niklas
  last_name: Dömer
- first_name: Felix
  full_name: Sauerwein, Felix
  last_name: Sauerwein
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Steffen
  full_name: Ganschow, Steffen
  last_name: Ganschow
- first_name: Mirco
  full_name: Imlau, Mirco
  last_name: Imlau
citation:
  ama: Hehemann T, Dömer N, Sauerwein F, Rüsing M, Ganschow S, Imlau M. Composition-dependent
    refractive index dispersion and Sellmeier coefficients for lithium niobate tantalate
    solid solutions. <i>Optical Materials Express</i>. 2026;16(7). doi:<a href="https://doi.org/10.1364/ome.592118">10.1364/ome.592118</a>
  apa: Hehemann, T., Dömer, N., Sauerwein, F., Rüsing, M., Ganschow, S., &#38; Imlau,
    M. (2026). Composition-dependent refractive index dispersion and Sellmeier coefficients
    for lithium niobate tantalate solid solutions. <i>Optical Materials Express</i>,
    <i>16</i>(7), Article 2069. <a href="https://doi.org/10.1364/ome.592118">https://doi.org/10.1364/ome.592118</a>
  bibtex: '@article{Hehemann_Dömer_Sauerwein_Rüsing_Ganschow_Imlau_2026, title={Composition-dependent
    refractive index dispersion and Sellmeier coefficients for lithium niobate tantalate
    solid solutions}, volume={16}, DOI={<a href="https://doi.org/10.1364/ome.592118">10.1364/ome.592118</a>},
    number={72069}, journal={Optical Materials Express}, publisher={Optica Publishing
    Group}, author={Hehemann, Tobias and Dömer, Niklas and Sauerwein, Felix and Rüsing,
    Michael and Ganschow, Steffen and Imlau, Mirco}, year={2026} }'
  chicago: Hehemann, Tobias, Niklas Dömer, Felix Sauerwein, Michael Rüsing, Steffen
    Ganschow, and Mirco Imlau. “Composition-Dependent Refractive Index Dispersion
    and Sellmeier Coefficients for Lithium Niobate Tantalate Solid Solutions.” <i>Optical
    Materials Express</i> 16, no. 7 (2026). <a href="https://doi.org/10.1364/ome.592118">https://doi.org/10.1364/ome.592118</a>.
  ieee: 'T. Hehemann, N. Dömer, F. Sauerwein, M. Rüsing, S. Ganschow, and M. Imlau,
    “Composition-dependent refractive index dispersion and Sellmeier coefficients
    for lithium niobate tantalate solid solutions,” <i>Optical Materials Express</i>,
    vol. 16, no. 7, Art. no. 2069, 2026, doi: <a href="https://doi.org/10.1364/ome.592118">10.1364/ome.592118</a>.'
  mla: Hehemann, Tobias, et al. “Composition-Dependent Refractive Index Dispersion
    and Sellmeier Coefficients for Lithium Niobate Tantalate Solid Solutions.” <i>Optical
    Materials Express</i>, vol. 16, no. 7, 2069, Optica Publishing Group, 2026, doi:<a
    href="https://doi.org/10.1364/ome.592118">10.1364/ome.592118</a>.
  short: T. Hehemann, N. Dömer, F. Sauerwein, M. Rüsing, S. Ganschow, M. Imlau, Optical
    Materials Express 16 (2026).
date_created: 2026-09-02T12:01:19Z
date_updated: 2026-09-02T12:06:36Z
department:
- _id: '288'
- _id: '15'
- _id: '623'
doi: 10.1364/ome.592118
funded_apc: '1'
intvolume: '        16'
issue: '7'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1364/OME.592118
oa: '1'
publication: Optical Materials Express
publication_identifier:
  issn:
  - 2159-3930
publication_status: published
publisher: Optica Publishing Group
quality_controlled: '1'
status: public
title: Composition-dependent refractive index dispersion and Sellmeier coefficients
  for lithium niobate tantalate solid solutions
type: journal_article
user_id: '22501'
volume: 16
year: '2026'
...
---
_id: '66944'
abstract:
- lang: eng
  text: "The comprehensive description of both the electrical transport along conductive
    domain walls in lithium niobate single crystals and the charge injection at the
    interfacing metal electrodes, emerged to be a complex challenge. Recently, a heuristic
    evaluation allowed to postulate the “\U0001D445⁢2⁢\U0001D437⁢2\r\n” equivalent-circuit
    model (consisting of two parallel resistor-diode pairs) to appropriately match
    the dc current-voltage (I-V) characteristics. Here, we carefully revisit the interfacial
    electrical behavior, i.e., the diode part of the equivalent circuit model, since
    many more processes beyond the diode-related electron hopping transport (HT) assumed
    so far, may concurrently occur, such as thermionic emission (TE), Fowler-Nordheim
    tunneling (FNT), space-charge limited conduction (SCLC), and others. The “\U0001D445⁢2⁢\U0001D437⁢2\r\n”
    model thus needs to be generalized into an “\U0001D445⁢2⁢\U0001D44B⁢2\r\n” circuit
    model (with \U0001D44B\r\n= HT, TE, FNT, SCLC, and others) to fit to the experimental
    data. Moreover, to check for the best I-V curve fitting to the different theories,
    we apply a higher-harmonic DW current-contribution analysis, i.e., an ac I-V inspection,
    that allows us to discriminate between all these possible models with much higher
    precision than from pure dc I-V curve fitting. Both the ac and dc analysis yield
    consistent results, finding that the FNT model accounts best for the domain-wall/electrode
    junctions investigated here."
article_number: '045406'
article_type: original
author:
- first_name: Manuel
  full_name: Zahn, Manuel
  last_name: Zahn
- first_name: Elke
  full_name: Beyreuther, Elke
  last_name: Beyreuther
- first_name: Iuliia
  full_name: Kiseleva, Iuliia
  last_name: Kiseleva
- first_name: Julius
  full_name: Ratzenberger, Julius
  last_name: Ratzenberger
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: 'Zahn M, Beyreuther E, Kiseleva I, Ratzenberger J, Rüsing M, Eng LM. Domain-wall/metal-electrode
    injection barrier in lithium niobate: Fowler-Nordheim tunneling fits best. <i>Physical
    Review B</i>. 2026;114(4). doi:<a href="https://doi.org/10.1103/3q26-4c3g">10.1103/3q26-4c3g</a>'
  apa: 'Zahn, M., Beyreuther, E., Kiseleva, I., Ratzenberger, J., Rüsing, M., &#38;
    Eng, L. M. (2026). Domain-wall/metal-electrode injection barrier in lithium niobate:
    Fowler-Nordheim tunneling fits best. <i>Physical Review B</i>, <i>114</i>(4),
    Article 045406. <a href="https://doi.org/10.1103/3q26-4c3g">https://doi.org/10.1103/3q26-4c3g</a>'
  bibtex: '@article{Zahn_Beyreuther_Kiseleva_Ratzenberger_Rüsing_Eng_2026, title={Domain-wall/metal-electrode
    injection barrier in lithium niobate: Fowler-Nordheim tunneling fits best}, volume={114},
    DOI={<a href="https://doi.org/10.1103/3q26-4c3g">10.1103/3q26-4c3g</a>}, number={4045406},
    journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Zahn,
    Manuel and Beyreuther, Elke and Kiseleva, Iuliia and Ratzenberger, Julius and
    Rüsing, Michael and Eng, Lukas M.}, year={2026} }'
  chicago: 'Zahn, Manuel, Elke Beyreuther, Iuliia Kiseleva, Julius Ratzenberger, Michael
    Rüsing, and Lukas M. Eng. “Domain-Wall/Metal-Electrode Injection Barrier in Lithium
    Niobate: Fowler-Nordheim Tunneling Fits Best.” <i>Physical Review B</i> 114, no.
    4 (2026). <a href="https://doi.org/10.1103/3q26-4c3g">https://doi.org/10.1103/3q26-4c3g</a>.'
  ieee: 'M. Zahn, E. Beyreuther, I. Kiseleva, J. Ratzenberger, M. Rüsing, and L. M.
    Eng, “Domain-wall/metal-electrode injection barrier in lithium niobate: Fowler-Nordheim
    tunneling fits best,” <i>Physical Review B</i>, vol. 114, no. 4, Art. no. 045406,
    2026, doi: <a href="https://doi.org/10.1103/3q26-4c3g">10.1103/3q26-4c3g</a>.'
  mla: 'Zahn, Manuel, et al. “Domain-Wall/Metal-Electrode Injection Barrier in Lithium
    Niobate: Fowler-Nordheim Tunneling Fits Best.” <i>Physical Review B</i>, vol.
    114, no. 4, 045406, American Physical Society (APS), 2026, doi:<a href="https://doi.org/10.1103/3q26-4c3g">10.1103/3q26-4c3g</a>.'
  short: M. Zahn, E. Beyreuther, I. Kiseleva, J. Ratzenberger, M. Rüsing, L.M. Eng,
    Physical Review B 114 (2026).
date_created: 2026-09-02T12:05:22Z
date_updated: 2026-09-02T12:05:53Z
doi: 10.1103/3q26-4c3g
intvolume: '       114'
issue: '4'
language:
- iso: eng
publication: Physical Review B
publication_identifier:
  issn:
  - 2469-9950
  - 2469-9969
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: 'Domain-wall/metal-electrode injection barrier in lithium niobate: Fowler-Nordheim
  tunneling fits best'
type: journal_article
user_id: '22501'
volume: 114
year: '2026'
...
---
_id: '65359'
abstract:
- lang: eng
  text: <jats:p>Lithium niobate sees widespread use in nonlinear and quantum optical
    devices, such as for sum- and difference-frequency generation or spontaneous parametric
    downconversion. In lithium niobate waveguides, nonlinear optical processes are
    often limited by the so-called photorefractive effect, which limits the maximum
    input or output powers and impacts the nonlinear spectral response. Therefore,
    strategies for the management of photorefractive damage are a key consideration
    in device design. Usually, the photorefractive damage threshold, i.e., the maximal
    permissible operating power, can be increased by high-temperature operation of
    devices. This approach, however, is not applicable in cryogenic environments,
    which may be required for specialized applications. To better understand the impact
    of photorefraction in nonlinear optical applications, we study the impact of photorefraction
    on the phase-matching spectra of two nonlinear-optical sum-frequency generation
    experiments at (1) high temperatures and (2) cryogenic temperatures. Furthermore,
    we present an approach to reduce the impact of photorefraction, which is compatible
    with cryogenic operation. This comprises an auxiliary light source, propagating
    in the same waveguide, which is used to restore phase-matching spectra impacted
    by photorefraction, as well as reduce pyroelectric effects. Our work provides
    an alternative route to photorefraction management applicable to cryogenic environments,
    as well as in situations with tight energy budgets, such as space applications.</jats:p>
article_number: '133105'
author:
- first_name: Nina Amelie
  full_name: Lange, Nina Amelie
  id: '56843'
  last_name: Lange
  orcid: 0000-0001-6624-7098
- first_name: René
  full_name: Pollmann, René
  id: '78890'
  last_name: Pollmann
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Michael
  full_name: Stefszky, Michael
  id: '42777'
  last_name: Stefszky
- first_name: Maximilian
  full_name: Protte, Maximilian
  id: '46170'
  last_name: Protte
- first_name: Raimund
  full_name: Ricken, Raimund
  last_name: Ricken
- first_name: Laura
  full_name: Padberg, Laura
  id: '40300'
  last_name: Padberg
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Tim
  full_name: Bartley, Tim
  last_name: Bartley
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
citation:
  ama: 'Lange NA, Pollmann R, Rüsing M, et al. Photorefraction management in lithium
    niobate waveguides: High-temperature vs cryogenic solutions. <i>Journal of Applied
    Physics</i>. 2026;139(13). doi:<a href="https://doi.org/10.1063/5.0324002">10.1063/5.0324002</a>'
  apa: 'Lange, N. A., Pollmann, R., Rüsing, M., Stefszky, M., Protte, M., Ricken,
    R., Padberg, L., Eigner, C., Bartley, T., &#38; Silberhorn, C. (2026). Photorefraction
    management in lithium niobate waveguides: High-temperature vs cryogenic solutions.
    <i>Journal of Applied Physics</i>, <i>139</i>(13), Article 133105. <a href="https://doi.org/10.1063/5.0324002">https://doi.org/10.1063/5.0324002</a>'
  bibtex: '@article{Lange_Pollmann_Rüsing_Stefszky_Protte_Ricken_Padberg_Eigner_Bartley_Silberhorn_2026,
    title={Photorefraction management in lithium niobate waveguides: High-temperature
    vs cryogenic solutions}, volume={139}, DOI={<a href="https://doi.org/10.1063/5.0324002">10.1063/5.0324002</a>},
    number={13133105}, journal={Journal of Applied Physics}, publisher={AIP Publishing},
    author={Lange, Nina Amelie and Pollmann, René and Rüsing, Michael and Stefszky,
    Michael and Protte, Maximilian and Ricken, Raimund and Padberg, Laura and Eigner,
    Christof and Bartley, Tim and Silberhorn, Christine}, year={2026} }'
  chicago: 'Lange, Nina Amelie, René Pollmann, Michael Rüsing, Michael Stefszky, Maximilian
    Protte, Raimund Ricken, Laura Padberg, Christof Eigner, Tim Bartley, and Christine
    Silberhorn. “Photorefraction Management in Lithium Niobate Waveguides: High-Temperature
    vs Cryogenic Solutions.” <i>Journal of Applied Physics</i> 139, no. 13 (2026).
    <a href="https://doi.org/10.1063/5.0324002">https://doi.org/10.1063/5.0324002</a>.'
  ieee: 'N. A. Lange <i>et al.</i>, “Photorefraction management in lithium niobate
    waveguides: High-temperature vs cryogenic solutions,” <i>Journal of Applied Physics</i>,
    vol. 139, no. 13, Art. no. 133105, 2026, doi: <a href="https://doi.org/10.1063/5.0324002">10.1063/5.0324002</a>.'
  mla: 'Lange, Nina Amelie, et al. “Photorefraction Management in Lithium Niobate
    Waveguides: High-Temperature vs Cryogenic Solutions.” <i>Journal of Applied Physics</i>,
    vol. 139, no. 13, 133105, AIP Publishing, 2026, doi:<a href="https://doi.org/10.1063/5.0324002">10.1063/5.0324002</a>.'
  short: N.A. Lange, R. Pollmann, M. Rüsing, M. Stefszky, M. Protte, R. Ricken, L.
    Padberg, C. Eigner, T. Bartley, C. Silberhorn, Journal of Applied Physics 139
    (2026).
date_created: 2026-04-07T08:41:07Z
date_updated: 2026-09-02T12:06:14Z
doi: 10.1063/5.0324002
intvolume: '       139'
issue: '13'
language:
- iso: eng
publication: Journal of Applied Physics
publication_identifier:
  issn:
  - 0021-8979
  - 1089-7550
publication_status: published
publisher: AIP Publishing
status: public
title: 'Photorefraction management in lithium niobate waveguides: High-temperature
  vs cryogenic solutions'
type: journal_article
user_id: '22501'
volume: 139
year: '2026'
...
---
_id: '61338'
abstract:
- lang: eng
  text: Conductive ferroelectric domain walls (DWs) represent a promising topical
    system for the development of nanoelectronic components and device sensors to
    be operational at elevated temperatures. DWs show very different properties as
    compared to their hosting bulk crystal, in particular with respect to the high
    local electrical conductivity. The objective of this work is to demonstrate DW
    conductivity up to temperatures as high as 400 °C which extends previous studies
    significantly. Experimental investigation of the DW conductivity of charged, inclined
    DWs is performed using 5 mol % MgO-doped lithium niobate single crystals. Current–voltage
    (  ) curves are determined by DC electrometer measurements and impedance spectroscopy
    and found to be identical. Moreover, impedance spectroscopy enables to recognize
    artifacts such as damaged electrodes. Temperature dependent measurements over
    repeated heating cycles reveal two distinct thermal activation energies for a
    given DW, with the higher of the activation energies only measured at higher temperatures.
    Depending on the specific sample, the higher activation energy is found above
    160 °C to 230 °C. This suggests, in turn, that more than one type of defect/polaron
    is involved, and that the dominant transport mechanism changes with increasing
    temperature. First principles atomistic modeling suggests that the conductivity
    of inclined domain walls cannot be solely explained by the formation of a 2D carrier
    gas and must be supported by hopping processes. This holds true even at temperatures
    as high as 400 °C. Our investigations underline the potential to extend DW current
    based nanoelectronic and sensor applications even into the so-far unexplored temperature
    range up to 400 °C.
article_number: '116949'
article_type: original
author:
- first_name: Hendrik
  full_name: Wulfmeier, Hendrik
  last_name: Wulfmeier
- first_name: Uliana
  full_name: Yakhnevych, Uliana
  last_name: Yakhnevych
- first_name: Cornelius
  full_name: Boekhoff, Cornelius
  last_name: Boekhoff
- first_name: Allan
  full_name: Diima, Allan
  last_name: Diima
- first_name: Marlo
  full_name: Kunzner, Marlo
  last_name: Kunzner
- first_name: Leonard M.
  full_name: Verhoff, Leonard M.
  last_name: Verhoff
- first_name: Jonas
  full_name: Paul, Jonas
  last_name: Paul
- first_name: Julius
  full_name: Ratzenberger, Julius
  last_name: Ratzenberger
- first_name: Elke
  full_name: Beyreuther, Elke
  last_name: Beyreuther
- first_name: Joshua
  full_name: Gössel, Joshua
  last_name: Gössel
- first_name: Iuliia
  full_name: Kiseleva, Iuliia
  last_name: Kiseleva
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
- first_name: Holger
  full_name: Fritze, Holger
  last_name: Fritze
citation:
  ama: Wulfmeier H, Yakhnevych U, Boekhoff C, et al. Demonstration of domain wall
    current in MgO-doped lithium niobate single crystals up to 400°C. <i>Solid State
    Ionics</i>. 2025;429. doi:<a href="https://doi.org/10.1016/j.ssi.2025.116949">10.1016/j.ssi.2025.116949</a>
  apa: Wulfmeier, H., Yakhnevych, U., Boekhoff, C., Diima, A., Kunzner, M., Verhoff,
    L. M., Paul, J., Ratzenberger, J., Beyreuther, E., Gössel, J., Kiseleva, I., Rüsing,
    M., Sanna, S., Eng, L. M., &#38; Fritze, H. (2025). Demonstration of domain wall
    current in MgO-doped lithium niobate single crystals up to 400°C. <i>Solid State
    Ionics</i>, <i>429</i>, Article 116949. <a href="https://doi.org/10.1016/j.ssi.2025.116949">https://doi.org/10.1016/j.ssi.2025.116949</a>
  bibtex: '@article{Wulfmeier_Yakhnevych_Boekhoff_Diima_Kunzner_Verhoff_Paul_Ratzenberger_Beyreuther_Gössel_et
    al._2025, title={Demonstration of domain wall current in MgO-doped lithium niobate
    single crystals up to 400°C}, volume={429}, DOI={<a href="https://doi.org/10.1016/j.ssi.2025.116949">10.1016/j.ssi.2025.116949</a>},
    number={116949}, journal={Solid State Ionics}, publisher={Elsevier BV}, author={Wulfmeier,
    Hendrik and Yakhnevych, Uliana and Boekhoff, Cornelius and Diima, Allan and Kunzner,
    Marlo and Verhoff, Leonard M. and Paul, Jonas and Ratzenberger, Julius and Beyreuther,
    Elke and Gössel, Joshua and et al.}, year={2025} }'
  chicago: Wulfmeier, Hendrik, Uliana Yakhnevych, Cornelius Boekhoff, Allan Diima,
    Marlo Kunzner, Leonard M. Verhoff, Jonas Paul, et al. “Demonstration of Domain
    Wall Current in MgO-Doped Lithium Niobate Single Crystals up to 400°C.” <i>Solid
    State Ionics</i> 429 (2025). <a href="https://doi.org/10.1016/j.ssi.2025.116949">https://doi.org/10.1016/j.ssi.2025.116949</a>.
  ieee: 'H. Wulfmeier <i>et al.</i>, “Demonstration of domain wall current in MgO-doped
    lithium niobate single crystals up to 400°C,” <i>Solid State Ionics</i>, vol.
    429, Art. no. 116949, 2025, doi: <a href="https://doi.org/10.1016/j.ssi.2025.116949">10.1016/j.ssi.2025.116949</a>.'
  mla: Wulfmeier, Hendrik, et al. “Demonstration of Domain Wall Current in MgO-Doped
    Lithium Niobate Single Crystals up to 400°C.” <i>Solid State Ionics</i>, vol.
    429, 116949, Elsevier BV, 2025, doi:<a href="https://doi.org/10.1016/j.ssi.2025.116949">10.1016/j.ssi.2025.116949</a>.
  short: H. Wulfmeier, U. Yakhnevych, C. Boekhoff, A. Diima, M. Kunzner, L.M. Verhoff,
    J. Paul, J. Ratzenberger, E. Beyreuther, J. Gössel, I. Kiseleva, M. Rüsing, S.
    Sanna, L.M. Eng, H. Fritze, Solid State Ionics 429 (2025).
date_created: 2025-09-17T16:18:18Z
date_updated: 2025-09-17T16:19:51Z
department:
- _id: '15'
- _id: '288'
- _id: '623'
doi: 10.1016/j.ssi.2025.116949
intvolume: '       429'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1016/j.ssi.2025.116949
oa: '1'
publication: Solid State Ionics
publication_identifier:
  issn:
  - 0167-2738
publication_status: published
publisher: Elsevier BV
quality_controlled: '1'
status: public
title: Demonstration of domain wall current in MgO-doped lithium niobate single crystals
  up to 400°C
type: journal_article
user_id: '22501'
volume: 429
year: '2025'
...
---
_id: '61337'
abstract:
- lang: eng
  text: <jats:p>Lithium niobate–tantalate mixed (LNT) crystals promise improved performance
    and new applications for optical, piezomechanical, or electrical devices when
    compared to the end composition compounds lithium niobate and lithium tantalate.
    The macroscopic properties of ferroelectrics highly depend on the structure of
    the underlying ferroelectric domains, which within mixed crystals can interact
    with the local changes in chemical compositions. In this work, we demonstrate
    how ferroelectric domain walls can unambiguously be identified and distinguished
    from local changes in composition by correlating piezoresponse force microscopy
    with second harmonic generation microscopy, using the Cherenkov contrast, reference
    crystal contrast, and negative phase mismatching contrast. We demonstrate how
    measuring the associated intensity change when approaching negative phase mismatching
    can be used to deduce the local tantalum concentration fast and over a large sample
    area. Based on these results, we study the natural domain structures that appear
    from Czochralski-grown, multi-domain LNT solid solution crystals. The developed
    results and methods serve as the central foundation to poling these mixed crystal
    systems and are key for their integration and applications.</jats:p>
article_number: '034101'
author:
- first_name: Boris
  full_name: Koppitz, Boris
  last_name: Koppitz
- first_name: Tanya
  full_name: Saxena, Tanya
  last_name: Saxena
- first_name: Felix
  full_name: Bernhardt, Felix
  last_name: Bernhardt
- first_name: Steffen
  full_name: Ganschow, Steffen
  last_name: Ganschow
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: Koppitz B, Saxena T, Bernhardt F, et al. Second harmonic generation contrasts
    of ferroelectric domain structures and composition in lithium niobate–tantalate
    mixed crystals. <i>Journal of Applied Physics</i>. 2025;138(3). doi:<a href="https://doi.org/10.1063/5.0276183">10.1063/5.0276183</a>
  apa: Koppitz, B., Saxena, T., Bernhardt, F., Ganschow, S., Sanna, S., Rüsing, M.,
    &#38; Eng, L. M. (2025). Second harmonic generation contrasts of ferroelectric
    domain structures and composition in lithium niobate–tantalate mixed crystals.
    <i>Journal of Applied Physics</i>, <i>138</i>(3), Article 034101. <a href="https://doi.org/10.1063/5.0276183">https://doi.org/10.1063/5.0276183</a>
  bibtex: '@article{Koppitz_Saxena_Bernhardt_Ganschow_Sanna_Rüsing_Eng_2025, title={Second
    harmonic generation contrasts of ferroelectric domain structures and composition
    in lithium niobate–tantalate mixed crystals}, volume={138}, DOI={<a href="https://doi.org/10.1063/5.0276183">10.1063/5.0276183</a>},
    number={3034101}, journal={Journal of Applied Physics}, publisher={AIP Publishing},
    author={Koppitz, Boris and Saxena, Tanya and Bernhardt, Felix and Ganschow, Steffen
    and Sanna, Simone and Rüsing, Michael and Eng, Lukas M.}, year={2025} }'
  chicago: Koppitz, Boris, Tanya Saxena, Felix Bernhardt, Steffen Ganschow, Simone
    Sanna, Michael Rüsing, and Lukas M. Eng. “Second Harmonic Generation Contrasts
    of Ferroelectric Domain Structures and Composition in Lithium Niobate–Tantalate
    Mixed Crystals.” <i>Journal of Applied Physics</i> 138, no. 3 (2025). <a href="https://doi.org/10.1063/5.0276183">https://doi.org/10.1063/5.0276183</a>.
  ieee: 'B. Koppitz <i>et al.</i>, “Second harmonic generation contrasts of ferroelectric
    domain structures and composition in lithium niobate–tantalate mixed crystals,”
    <i>Journal of Applied Physics</i>, vol. 138, no. 3, Art. no. 034101, 2025, doi:
    <a href="https://doi.org/10.1063/5.0276183">10.1063/5.0276183</a>.'
  mla: Koppitz, Boris, et al. “Second Harmonic Generation Contrasts of Ferroelectric
    Domain Structures and Composition in Lithium Niobate–Tantalate Mixed Crystals.”
    <i>Journal of Applied Physics</i>, vol. 138, no. 3, 034101, AIP Publishing, 2025,
    doi:<a href="https://doi.org/10.1063/5.0276183">10.1063/5.0276183</a>.
  short: B. Koppitz, T. Saxena, F. Bernhardt, S. Ganschow, S. Sanna, M. Rüsing, L.M.
    Eng, Journal of Applied Physics 138 (2025).
date_created: 2025-09-17T16:16:04Z
date_updated: 2025-09-17T16:18:02Z
department:
- _id: '15'
- _id: '623'
doi: 10.1063/5.0276183
funded_apc: '1'
intvolume: '       138'
issue: '3'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://pubs.aip.org/aip/jap/article/138/3/034101/3352909
oa: '1'
publication: Journal of Applied Physics
publication_identifier:
  issn:
  - 0021-8979
  - 1089-7550
publication_status: published
publisher: AIP Publishing
quality_controlled: '1'
status: public
title: Second harmonic generation contrasts of ferroelectric domain structures and
  composition in lithium niobate–tantalate mixed crystals
type: journal_article
user_id: '22501'
volume: 138
year: '2025'
...
---
_id: '62749'
abstract:
- lang: eng
  text: "Coherent Raman scattering techniques as coherent anti-Stokes Raman scattering
    (CARS), offer significant advantages in terms of pixel dwell times and speed as
    compared to spontaneous Raman scattering for investigations of crystalline materials.
    However, the spectral information in CARS is often hampered by the presence of
    a nonresonant contribution to the scattering process that shifts and distorts
    the Raman peaks. In this work, we apply a method to obtain nonresonant background-free
    spectra based on time-delayed, broadband CARS (TD-BCARS) using an intrapulse excitation
    scheme. In particular, this method can measure the phononic dephasing times across
    the full phonon spectrum at once. We test the methodology on amorphous SiO2 (glass),
    which is used to characterize the setup-specific and material-independent response
    times, and then apply TD-BCARS to the analysis of single crystals of diamond and
    ferroelectrics of potassium titanyl phosphate (KTP) and potassium titanyl arsenate
    (KTA). For diamond, we determine a dephasing time of \U0001D70F=7.81 ps for the
    single \U0001D460⁢\U0001D45D3 peak."
article_number: '224106'
article_type: original
author:
- first_name: F.
  full_name: Hempel, F.
  last_name: Hempel
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: F.
  full_name: Vernuccio, F.
  last_name: Vernuccio
- first_name: K. J.
  full_name: Spychala, K. J.
  last_name: Spychala
- first_name: R.
  full_name: Buschbeck, R.
  last_name: Buschbeck
- first_name: G.
  full_name: Cerullo, G.
  last_name: Cerullo
- first_name: D.
  full_name: Polli, D.
  last_name: Polli
- first_name: L. M.
  full_name: Eng, L. M.
  last_name: Eng
citation:
  ama: Hempel F, Rüsing M, Vernuccio F, et al. Phonon dephasing times determined with
    time-delayed broadband coherent anti-Stokes Raman scattering. <i>Physical Review
    B</i>. 2025;112(22). doi:<a href="https://doi.org/10.1103/1ctr-csjy">10.1103/1ctr-csjy</a>
  apa: Hempel, F., Rüsing, M., Vernuccio, F., Spychala, K. J., Buschbeck, R., Cerullo,
    G., Polli, D., &#38; Eng, L. M. (2025). Phonon dephasing times determined with
    time-delayed broadband coherent anti-Stokes Raman scattering. <i>Physical Review
    B</i>, <i>112</i>(22), Article 224106. <a href="https://doi.org/10.1103/1ctr-csjy">https://doi.org/10.1103/1ctr-csjy</a>
  bibtex: '@article{Hempel_Rüsing_Vernuccio_Spychala_Buschbeck_Cerullo_Polli_Eng_2025,
    title={Phonon dephasing times determined with time-delayed broadband coherent
    anti-Stokes Raman scattering}, volume={112}, DOI={<a href="https://doi.org/10.1103/1ctr-csjy">10.1103/1ctr-csjy</a>},
    number={22224106}, journal={Physical Review B}, publisher={American Physical Society
    (APS)}, author={Hempel, F. and Rüsing, Michael and Vernuccio, F. and Spychala,
    K. J. and Buschbeck, R. and Cerullo, G. and Polli, D. and Eng, L. M.}, year={2025}
    }'
  chicago: Hempel, F., Michael Rüsing, F. Vernuccio, K. J. Spychala, R. Buschbeck,
    G. Cerullo, D. Polli, and L. M. Eng. “Phonon Dephasing Times Determined with Time-Delayed
    Broadband Coherent Anti-Stokes Raman Scattering.” <i>Physical Review B</i> 112,
    no. 22 (2025). <a href="https://doi.org/10.1103/1ctr-csjy">https://doi.org/10.1103/1ctr-csjy</a>.
  ieee: 'F. Hempel <i>et al.</i>, “Phonon dephasing times determined with time-delayed
    broadband coherent anti-Stokes Raman scattering,” <i>Physical Review B</i>, vol.
    112, no. 22, Art. no. 224106, 2025, doi: <a href="https://doi.org/10.1103/1ctr-csjy">10.1103/1ctr-csjy</a>.'
  mla: Hempel, F., et al. “Phonon Dephasing Times Determined with Time-Delayed Broadband
    Coherent Anti-Stokes Raman Scattering.” <i>Physical Review B</i>, vol. 112, no.
    22, 224106, American Physical Society (APS), 2025, doi:<a href="https://doi.org/10.1103/1ctr-csjy">10.1103/1ctr-csjy</a>.
  short: F. Hempel, M. Rüsing, F. Vernuccio, K.J. Spychala, R. Buschbeck, G. Cerullo,
    D. Polli, L.M. Eng, Physical Review B 112 (2025).
date_created: 2025-12-02T19:21:33Z
date_updated: 2025-12-02T19:23:55Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1103/1ctr-csjy
external_id:
  arxiv:
  - '2506.05519'
intvolume: '       112'
issue: '22'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2506.05519
oa: '1'
publication: Physical Review B
publication_identifier:
  issn:
  - 2469-9950
  - 2469-9969
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: Phonon dephasing times determined with time-delayed broadband coherent anti-Stokes
  Raman scattering
type: journal_article
user_id: '22501'
volume: 112
year: '2025'
...
---
_id: '62713'
abstract:
- lang: eng
  text: Periodically poled thin-film lithium niobate (TFLN) crystals are the fundamental
    building block for highly-efficient quantum light sources and frequency converters.
    The efficiency of these devices is strongly dependent on the interaction length
    between the light and the nonlinear material, scaling quadratically with this
    parameter. Nevertheless, the fabrication of long, continuously poled areas in
    TFLN remains challenging, the length of continuously poled areas rarely exceeds
    10 mm. In this work, we demonstrate a significant progress in this field achieving
    the periodic poling of continuous poled areas of 70 mm length with a 3 μm poling
    period and a close to 50 % duty cycle. We compare two poling electrode design
    approaches to fabricate long, continuous poled areas. The first approach involves
    the poling of a single, continuous 70 mm long electrode. The second utilize a
    segmented approach including the poling of more than 20 individual sections forming
    together a 70 mm long poling area with no stitching errors. While the continuous
    electrode allows for faster fabrication, the segmented approach allows to individually
    optimize the poling resulting in less duty cycle variation. A detailed analysis
    of the periodic poling results reveals that the results of both are consistent
    with previously reported poling outcomes for shorter devices. Thus, we demonstrate
    wafer-scale periodic poling exceeding chiplet-size without any loss in the periodic
    poling quality. Our work presents a key step towards highly-efficient, narrow-bandwidth
    and low-pump power nonlinear optical devices.
article_type: original
author:
- first_name: Laura
  full_name: Bollmers, Laura
  id: '61375'
  last_name: Bollmers
- first_name: Noah
  full_name: Spiegelberg, Noah
  last_name: Spiegelberg
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Laura
  full_name: Padberg, Laura
  id: '40300'
  last_name: Padberg
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
citation:
  ama: Bollmers L, Spiegelberg N, Rüsing M, Eigner C, Padberg L, Silberhorn C. Segmented
    finger electrodes to optimize ultra-long continuous wafer-scale periodic poling
    in thin-film lithium niobate. <i>Nanophotonics</i>. 2025;14:4761. doi:<a href="https://doi.org/10.1515/nanoph-2025-0461">10.1515/nanoph-2025-0461</a>
  apa: Bollmers, L., Spiegelberg, N., Rüsing, M., Eigner, C., Padberg, L., &#38; Silberhorn,
    C. (2025). Segmented finger electrodes to optimize ultra-long continuous wafer-scale
    periodic poling in thin-film lithium niobate. <i>Nanophotonics</i>, <i>14</i>,
    4761. <a href="https://doi.org/10.1515/nanoph-2025-0461">https://doi.org/10.1515/nanoph-2025-0461</a>
  bibtex: '@article{Bollmers_Spiegelberg_Rüsing_Eigner_Padberg_Silberhorn_2025, title={Segmented
    finger electrodes to optimize ultra-long continuous wafer-scale periodic poling
    in thin-film lithium niobate}, volume={14}, DOI={<a href="https://doi.org/10.1515/nanoph-2025-0461">10.1515/nanoph-2025-0461</a>},
    journal={Nanophotonics}, publisher={Walter de Gruyter GmbH}, author={Bollmers,
    Laura and Spiegelberg, Noah and Rüsing, Michael and Eigner, Christof and Padberg,
    Laura and Silberhorn, Christine}, year={2025}, pages={4761} }'
  chicago: 'Bollmers, Laura, Noah Spiegelberg, Michael Rüsing, Christof Eigner, Laura
    Padberg, and Christine Silberhorn. “Segmented Finger Electrodes to Optimize Ultra-Long
    Continuous Wafer-Scale Periodic Poling in Thin-Film Lithium Niobate.” <i>Nanophotonics</i>
    14 (2025): 4761. <a href="https://doi.org/10.1515/nanoph-2025-0461">https://doi.org/10.1515/nanoph-2025-0461</a>.'
  ieee: 'L. Bollmers, N. Spiegelberg, M. Rüsing, C. Eigner, L. Padberg, and C. Silberhorn,
    “Segmented finger electrodes to optimize ultra-long continuous wafer-scale periodic
    poling in thin-film lithium niobate,” <i>Nanophotonics</i>, vol. 14, p. 4761,
    2025, doi: <a href="https://doi.org/10.1515/nanoph-2025-0461">10.1515/nanoph-2025-0461</a>.'
  mla: Bollmers, Laura, et al. “Segmented Finger Electrodes to Optimize Ultra-Long
    Continuous Wafer-Scale Periodic Poling in Thin-Film Lithium Niobate.” <i>Nanophotonics</i>,
    vol. 14, Walter de Gruyter GmbH, 2025, p. 4761, doi:<a href="https://doi.org/10.1515/nanoph-2025-0461">10.1515/nanoph-2025-0461</a>.
  short: L. Bollmers, N. Spiegelberg, M. Rüsing, C. Eigner, L. Padberg, C. Silberhorn,
    Nanophotonics 14 (2025) 4761.
date_created: 2025-12-01T08:45:07Z
date_updated: 2026-01-07T12:06:29Z
department:
- _id: '15'
- _id: '288'
- _id: '623'
doi: 10.1515/nanoph-2025-0461
intvolume: '        14'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1515/nanoph-2025-0461
oa: '1'
page: '4761'
publication: Nanophotonics
publication_identifier:
  issn:
  - 2192-8606
  - 2192-8614
publication_status: published
publisher: Walter de Gruyter GmbH
quality_controlled: '1'
status: public
title: Segmented finger electrodes to optimize ultra-long continuous wafer-scale periodic
  poling in thin-film lithium niobate
type: journal_article
user_id: '22501'
volume: 14
year: '2025'
...
---
_id: '59276'
abstract:
- lang: eng
  text: Stress plays a crucial role in thin films and layered systems, and thus significantly
    influences the material's electrical, mechanical and (nonlinear) optical responses.
    Despite lithium niobate's wide applicability as a nonlinear optical material,
    the impact of mechanical stress on its nonlinear optical properties is not well
    characterized. In this work, we systematically study both experimentally and theoretically,
    the nonlinear optical responses of thin film lithium niobate (TFLN) single crystals.
    Compressive and tensile stress is applied in our experiment using a piezodriven
    strain cell. We then record the second-harmonic-generated (SHG) response in back-reflection
    geometry, and compare these results to theoretical modeling using density functional
    theory (DFT). Both methods consistently reveal that uniaxial stress induces changes
    of the nonlinear optical susceptibility of certain tensor elements on the order
    of up to 1 pm/(V GPa). The exact value depends on the tensor element that is addressed
    in our SHG analysis, on the crystal orientation, and also whether using compressive
    or tensile stresses. Furthermore, a lowering of the crystal symmetry when applying
    stress along the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>x</a:mi></a:math>
    or <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>y</b:mi></b:math>
    crystallographic axes is observed by the appearance of new nonlinear optical tensor
    elements within the strained crystals.
article_number: '064109'
author:
- first_name: Mike N.
  full_name: Pionteck, Mike N.
  last_name: Pionteck
- first_name: Matthias
  full_name: Roeper, Matthias
  last_name: Roeper
- first_name: Boris
  full_name: Koppitz, Boris
  last_name: Koppitz
- first_name: Samuel D.
  full_name: Seddon, Samuel D.
  last_name: Seddon
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Laura
  full_name: Padberg, Laura
  id: '40300'
  last_name: Padberg
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: Pionteck MN, Roeper M, Koppitz B, et al. Second-order nonlinear piezo-optic
    properties of single crystal lithium niobate thin films. <i>Physical Review B</i>.
    2025;111(6). doi:<a href="https://doi.org/10.1103/physrevb.111.064109">10.1103/physrevb.111.064109</a>
  apa: Pionteck, M. N., Roeper, M., Koppitz, B., Seddon, S. D., Rüsing, M., Padberg,
    L., Eigner, C., Silberhorn, C., Sanna, S., &#38; Eng, L. M. (2025). Second-order
    nonlinear piezo-optic properties of single crystal lithium niobate thin films.
    <i>Physical Review B</i>, <i>111</i>(6), Article 064109. <a href="https://doi.org/10.1103/physrevb.111.064109">https://doi.org/10.1103/physrevb.111.064109</a>
  bibtex: '@article{Pionteck_Roeper_Koppitz_Seddon_Rüsing_Padberg_Eigner_Silberhorn_Sanna_Eng_2025,
    title={Second-order nonlinear piezo-optic properties of single crystal lithium
    niobate thin films}, volume={111}, DOI={<a href="https://doi.org/10.1103/physrevb.111.064109">10.1103/physrevb.111.064109</a>},
    number={6064109}, journal={Physical Review B}, publisher={American Physical Society
    (APS)}, author={Pionteck, Mike N. and Roeper, Matthias and Koppitz, Boris and
    Seddon, Samuel D. and Rüsing, Michael and Padberg, Laura and Eigner, Christof
    and Silberhorn, Christine and Sanna, Simone and Eng, Lukas M.}, year={2025} }'
  chicago: Pionteck, Mike N., Matthias Roeper, Boris Koppitz, Samuel D. Seddon, Michael
    Rüsing, Laura Padberg, Christof Eigner, Christine Silberhorn, Simone Sanna, and
    Lukas M. Eng. “Second-Order Nonlinear Piezo-Optic Properties of Single Crystal
    Lithium Niobate Thin Films.” <i>Physical Review B</i> 111, no. 6 (2025). <a href="https://doi.org/10.1103/physrevb.111.064109">https://doi.org/10.1103/physrevb.111.064109</a>.
  ieee: 'M. N. Pionteck <i>et al.</i>, “Second-order nonlinear piezo-optic properties
    of single crystal lithium niobate thin films,” <i>Physical Review B</i>, vol.
    111, no. 6, Art. no. 064109, 2025, doi: <a href="https://doi.org/10.1103/physrevb.111.064109">10.1103/physrevb.111.064109</a>.'
  mla: Pionteck, Mike N., et al. “Second-Order Nonlinear Piezo-Optic Properties of
    Single Crystal Lithium Niobate Thin Films.” <i>Physical Review B</i>, vol. 111,
    no. 6, 064109, American Physical Society (APS), 2025, doi:<a href="https://doi.org/10.1103/physrevb.111.064109">10.1103/physrevb.111.064109</a>.
  short: M.N. Pionteck, M. Roeper, B. Koppitz, S.D. Seddon, M. Rüsing, L. Padberg,
    C. Eigner, C. Silberhorn, S. Sanna, L.M. Eng, Physical Review B 111 (2025).
date_created: 2025-04-02T16:21:47Z
date_updated: 2025-04-02T16:24:47Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1103/physrevb.111.064109
intvolume: '       111'
issue: '6'
language:
- iso: eng
publication: Physical Review B
publication_identifier:
  issn:
  - 2469-9950
  - 2469-9969
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: Second-order nonlinear piezo-optic properties of single crystal lithium niobate
  thin films
type: journal_article
user_id: '22501'
volume: 111
year: '2025'
...
---
_id: '60566'
article_number: '074402'
author:
- first_name: Adriana
  full_name: Bocchini, Adriana
  id: '58349'
  last_name: Bocchini
  orcid: 0000-0002-2134-3075
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Laura
  full_name: Bollmers, Laura
  id: '61375'
  last_name: Bollmers
- first_name: Sebastian
  full_name: Lengeling, Sebastian
  id: '44373'
  last_name: Lengeling
- first_name: Philipp
  full_name: Mues, Philipp
  id: '49772'
  last_name: Mues
  orcid: 0000-0003-0643-7636
- first_name: Laura
  full_name: Padberg, Laura
  id: '40300'
  last_name: Padberg
- first_name: Uwe
  full_name: Gerstmann, Uwe
  id: '171'
  last_name: Gerstmann
  orcid: 0000-0002-4476-223X
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Wolf Gero
  full_name: Schmidt, Wolf Gero
  id: '468'
  last_name: Schmidt
  orcid: 0000-0002-2717-5076
citation:
  ama: 'Bocchini A, Rüsing M, Bollmers L, et al. Mg dopants in lithium niobate: Defect
    models and impact on domain inversion. <i>Physical Review Materials</i>. 2025;9(7).
    doi:<a href="https://doi.org/10.1103/5wz1-bjyr">10.1103/5wz1-bjyr</a>'
  apa: 'Bocchini, A., Rüsing, M., Bollmers, L., Lengeling, S., Mues, P., Padberg,
    L., Gerstmann, U., Silberhorn, C., Eigner, C., &#38; Schmidt, W. G. (2025). Mg
    dopants in lithium niobate: Defect models and impact on domain inversion. <i>Physical
    Review Materials</i>, <i>9</i>(7), Article 074402. <a href="https://doi.org/10.1103/5wz1-bjyr">https://doi.org/10.1103/5wz1-bjyr</a>'
  bibtex: '@article{Bocchini_Rüsing_Bollmers_Lengeling_Mues_Padberg_Gerstmann_Silberhorn_Eigner_Schmidt_2025,
    title={Mg dopants in lithium niobate: Defect models and impact on domain inversion},
    volume={9}, DOI={<a href="https://doi.org/10.1103/5wz1-bjyr">10.1103/5wz1-bjyr</a>},
    number={7074402}, journal={Physical Review Materials}, publisher={American Physical
    Society (APS)}, author={Bocchini, Adriana and Rüsing, Michael and Bollmers, Laura
    and Lengeling, Sebastian and Mues, Philipp and Padberg, Laura and Gerstmann, Uwe
    and Silberhorn, Christine and Eigner, Christof and Schmidt, Wolf Gero}, year={2025}
    }'
  chicago: 'Bocchini, Adriana, Michael Rüsing, Laura Bollmers, Sebastian Lengeling,
    Philipp Mues, Laura Padberg, Uwe Gerstmann, Christine Silberhorn, Christof Eigner,
    and Wolf Gero Schmidt. “Mg Dopants in Lithium Niobate: Defect Models and Impact
    on Domain Inversion.” <i>Physical Review Materials</i> 9, no. 7 (2025). <a href="https://doi.org/10.1103/5wz1-bjyr">https://doi.org/10.1103/5wz1-bjyr</a>.'
  ieee: 'A. Bocchini <i>et al.</i>, “Mg dopants in lithium niobate: Defect models
    and impact on domain inversion,” <i>Physical Review Materials</i>, vol. 9, no.
    7, Art. no. 074402, 2025, doi: <a href="https://doi.org/10.1103/5wz1-bjyr">10.1103/5wz1-bjyr</a>.'
  mla: 'Bocchini, Adriana, et al. “Mg Dopants in Lithium Niobate: Defect Models and
    Impact on Domain Inversion.” <i>Physical Review Materials</i>, vol. 9, no. 7,
    074402, American Physical Society (APS), 2025, doi:<a href="https://doi.org/10.1103/5wz1-bjyr">10.1103/5wz1-bjyr</a>.'
  short: A. Bocchini, M. Rüsing, L. Bollmers, S. Lengeling, P. Mues, L. Padberg, U.
    Gerstmann, C. Silberhorn, C. Eigner, W.G. Schmidt, Physical Review Materials 9
    (2025).
date_created: 2025-07-09T09:13:24Z
date_updated: 2026-03-17T17:50:06Z
ddc:
- '530'
department:
- _id: '15'
- _id: '623'
- _id: '295'
- _id: '790'
- _id: '288'
- _id: '230'
- _id: '429'
- _id: '35'
- _id: '170'
- _id: '169'
- _id: '27'
doi: 10.1103/5wz1-bjyr
file:
- access_level: open_access
  content_type: application/pdf
  creator: adrianab
  date_created: 2025-07-09T09:18:45Z
  date_updated: 2025-07-10T06:43:34Z
  file_id: '60567'
  file_name: Mg_dopants_LN_PRM.pdf
  file_size: 4175120
  relation: main_file
file_date_updated: 2025-07-10T06:43:34Z
has_accepted_license: '1'
intvolume: '         9'
issue: '7'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://link.aps.org/doi/10.1103/5wz1-bjyr
oa: '1'
project:
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
- _id: '53'
  name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden
    Konzepten zu funktionellen Strukturen'
- _id: '55'
  name: 'TRR 142 - B: TRR 142 - Project Area B'
- _id: '54'
  name: 'TRR 142 - A: TRR 142 - Project Area A'
- _id: '168'
  name: 'TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften
    von Lithiumniobat (B07*)'
- _id: '166'
  name: 'TRR 142 - A11: TRR 142 - Subproject A11'
publication: Physical Review Materials
publication_identifier:
  issn:
  - 2475-9953
publication_status: published
publisher: American Physical Society (APS)
status: public
title: 'Mg dopants in lithium niobate: Defect models and impact on domain inversion'
type: journal_article
user_id: '22501'
volume: 9
year: '2025'
...
---
_id: '51156'
abstract:
- lang: eng
  text: 'Ferroelectric domain wall (DW) conductivity (DWC) can be attributed to two
    separate mechanisms: (a) the injection/ejection of charge carriers across the
    Schottky barrier formed at the (metal-)electrode-DW junction and (b) the transport
    of those charge carriers along the DW. Current-voltage (I-U) characteristics,
    recorded at variable temperatures from LiNbO3 (LNO) DWs, are clearly able to differentiate
    between these two contributions. Practically, they allow us to directly quantify
    the physical parameters relevant to the two mechanisms (a) and (b) mentioned above.
    These are, for example, the resistance of the DW, the saturation current, the
    ideality factor, and the Schottky barrier height of the electrode-DW junction.
    Furthermore, the activation energies needed to initiate the thermally activated
    electronic transport along the DWs can be extracted. In addition, we show that
    electronic transport along LNO DWs can be elegantly viewed and interpreted in
    an adapted semiconductor picture based on a double-diode, double-resistor equivalent-circuit
    model, the R2D2 model. Finally, our R2D2 model was checked for its universality
    by successfully fitting the I-U curves of not only z-cut LNO bulk DWs, but equally
    of z-cut thin-film LNO DWs, and of x-cut thin-film DWs as reported in literature.'
article_number: '024007'
article_type: original
author:
- first_name: Manuel
  full_name: Zahn, Manuel
  last_name: Zahn
- first_name: Elke
  full_name: Beyreuther, Elke
  last_name: Beyreuther
- first_name: Iuliia
  full_name: Kiseleva, Iuliia
  last_name: Kiseleva
- first_name: Ahmed Samir
  full_name: Lotfy, Ahmed Samir
  last_name: Lotfy
- first_name: Conor J.
  full_name: McCluskey, Conor J.
  last_name: McCluskey
- first_name: Jesi R.
  full_name: Maguire, Jesi R.
  last_name: Maguire
- first_name: Ahmet
  full_name: Suna, Ahmet
  last_name: Suna
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: J. Marty
  full_name: Gregg, J. Marty
  last_name: Gregg
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: Zahn M, Beyreuther E, Kiseleva I, et al. Equivalent-circuit model that quantitatively
    describes domain-wall conductivity in ferroelectric lithium . <i>Physical Review
    Applied</i>. 2024;21(2). doi:<a href="https://doi.org/10.1103/physrevapplied.21.024007">10.1103/physrevapplied.21.024007</a>
  apa: Zahn, M., Beyreuther, E., Kiseleva, I., Lotfy, A. S., McCluskey, C. J., Maguire,
    J. R., Suna, A., Rüsing, M., Gregg, J. M., &#38; Eng, L. M. (2024). Equivalent-circuit
    model that quantitatively describes domain-wall conductivity in ferroelectric
    lithium . <i>Physical Review Applied</i>, <i>21</i>(2), Article 024007. <a href="https://doi.org/10.1103/physrevapplied.21.024007">https://doi.org/10.1103/physrevapplied.21.024007</a>
  bibtex: '@article{Zahn_Beyreuther_Kiseleva_Lotfy_McCluskey_Maguire_Suna_Rüsing_Gregg_Eng_2024,
    title={Equivalent-circuit model that quantitatively describes domain-wall conductivity
    in ferroelectric lithium }, volume={21}, DOI={<a href="https://doi.org/10.1103/physrevapplied.21.024007">10.1103/physrevapplied.21.024007</a>},
    number={2024007}, journal={Physical Review Applied}, publisher={American Physical
    Society (APS)}, author={Zahn, Manuel and Beyreuther, Elke and Kiseleva, Iuliia
    and Lotfy, Ahmed Samir and McCluskey, Conor J. and Maguire, Jesi R. and Suna,
    Ahmet and Rüsing, Michael and Gregg, J. Marty and Eng, Lukas M.}, year={2024}
    }'
  chicago: Zahn, Manuel, Elke Beyreuther, Iuliia Kiseleva, Ahmed Samir Lotfy, Conor
    J. McCluskey, Jesi R. Maguire, Ahmet Suna, Michael Rüsing, J. Marty Gregg, and
    Lukas M. Eng. “Equivalent-Circuit Model That Quantitatively Describes Domain-Wall
    Conductivity in Ferroelectric Lithium .” <i>Physical Review Applied</i> 21, no.
    2 (2024). <a href="https://doi.org/10.1103/physrevapplied.21.024007">https://doi.org/10.1103/physrevapplied.21.024007</a>.
  ieee: 'M. Zahn <i>et al.</i>, “Equivalent-circuit model that quantitatively describes
    domain-wall conductivity in ferroelectric lithium ,” <i>Physical Review Applied</i>,
    vol. 21, no. 2, Art. no. 024007, 2024, doi: <a href="https://doi.org/10.1103/physrevapplied.21.024007">10.1103/physrevapplied.21.024007</a>.'
  mla: Zahn, Manuel, et al. “Equivalent-Circuit Model That Quantitatively Describes
    Domain-Wall Conductivity in Ferroelectric Lithium .” <i>Physical Review Applied</i>,
    vol. 21, no. 2, 024007, American Physical Society (APS), 2024, doi:<a href="https://doi.org/10.1103/physrevapplied.21.024007">10.1103/physrevapplied.21.024007</a>.
  short: M. Zahn, E. Beyreuther, I. Kiseleva, A.S. Lotfy, C.J. McCluskey, J.R. Maguire,
    A. Suna, M. Rüsing, J.M. Gregg, L.M. Eng, Physical Review Applied 21 (2024).
date_created: 2024-02-06T08:02:15Z
date_updated: 2024-02-06T08:08:09Z
department:
- _id: '15'
- _id: '169'
- _id: '623'
- _id: '288'
doi: 10.1103/physrevapplied.21.024007
intvolume: '        21'
issue: '2'
keyword:
- General Physics and Astronomy
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2307.10322
oa: '1'
publication: Physical Review Applied
publication_identifier:
  issn:
  - 2331-7019
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: 'Equivalent-circuit model that quantitatively describes domain-wall conductivity
  in ferroelectric lithium '
type: journal_article
user_id: '22501'
volume: 21
year: '2024'
...
---
_id: '55085'
abstract:
- lang: eng
  text: The lithium niobate–lithium tantalate solid solution’s phase diagram was investigated
    using experimental data from differential thermal analysis (DTA) and crystal growth.
    We used XRF analysis to determine the elemental composition of the crystals. The
    Neumann–Kopp rule provided essential data for the end members lithium niobate
    (LN) and lithium tantalate (LT). The heats of fusion of the end members, given
    by DTA measurements, are 103 kJ/mol at 1531 K for LN and 289 kJ/mol at 1913 K
    for LT. These values were used as input parameters to generate the data. This
    data served as the basis for calculating a phase diagram for LN-LT solid solutions.
    Finally, based on the experimental data and a thermodynamic solution model, the
    Calphad Factsage module optimized the phase diagram. We also generated thermodynamic
    parameters for Gibbs’ excess energy of the solid solution. A plot of the segregation
    coefficient as a function of Ta concentration was derived from the phase diagram.
author:
- first_name: Umar
  full_name: Bashir, Umar
  last_name: Bashir
- first_name: Detlef
  full_name: Klimm, Detlef
  last_name: Klimm
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Matthias
  full_name: Bickermann, Matthias
  last_name: Bickermann
- first_name: Steffen
  full_name: Ganschow, Steffen
  last_name: Ganschow
citation:
  ama: Bashir U, Klimm D, Rüsing M, Bickermann M, Ganschow S. Evaluation and thermodynamic
    optimization of phase diagram of lithium niobate tantalate solid solutions. <i>Journal
    of Materials Science</i>. Published online 2024. doi:<a href="https://doi.org/10.1007/s10853-024-09932-7">10.1007/s10853-024-09932-7</a>
  apa: Bashir, U., Klimm, D., Rüsing, M., Bickermann, M., &#38; Ganschow, S. (2024).
    Evaluation and thermodynamic optimization of phase diagram of lithium niobate
    tantalate solid solutions. <i>Journal of Materials Science</i>. <a href="https://doi.org/10.1007/s10853-024-09932-7">https://doi.org/10.1007/s10853-024-09932-7</a>
  bibtex: '@article{Bashir_Klimm_Rüsing_Bickermann_Ganschow_2024, title={Evaluation
    and thermodynamic optimization of phase diagram of lithium niobate tantalate solid
    solutions}, DOI={<a href="https://doi.org/10.1007/s10853-024-09932-7">10.1007/s10853-024-09932-7</a>},
    journal={Journal of Materials Science}, publisher={Springer Science and Business
    Media LLC}, author={Bashir, Umar and Klimm, Detlef and Rüsing, Michael and Bickermann,
    Matthias and Ganschow, Steffen}, year={2024} }'
  chicago: Bashir, Umar, Detlef Klimm, Michael Rüsing, Matthias Bickermann, and Steffen
    Ganschow. “Evaluation and Thermodynamic Optimization of Phase Diagram of Lithium
    Niobate Tantalate Solid Solutions.” <i>Journal of Materials Science</i>, 2024.
    <a href="https://doi.org/10.1007/s10853-024-09932-7">https://doi.org/10.1007/s10853-024-09932-7</a>.
  ieee: 'U. Bashir, D. Klimm, M. Rüsing, M. Bickermann, and S. Ganschow, “Evaluation
    and thermodynamic optimization of phase diagram of lithium niobate tantalate solid
    solutions,” <i>Journal of Materials Science</i>, 2024, doi: <a href="https://doi.org/10.1007/s10853-024-09932-7">10.1007/s10853-024-09932-7</a>.'
  mla: Bashir, Umar, et al. “Evaluation and Thermodynamic Optimization of Phase Diagram
    of Lithium Niobate Tantalate Solid Solutions.” <i>Journal of Materials Science</i>,
    Springer Science and Business Media LLC, 2024, doi:<a href="https://doi.org/10.1007/s10853-024-09932-7">10.1007/s10853-024-09932-7</a>.
  short: U. Bashir, D. Klimm, M. Rüsing, M. Bickermann, S. Ganschow, Journal of Materials
    Science (2024).
date_created: 2024-07-05T06:47:53Z
date_updated: 2024-07-05T06:49:25Z
department:
- _id: '15'
- _id: '169'
- _id: '623'
doi: 10.1007/s10853-024-09932-7
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1007/s10853-024-09932-7
oa: '1'
publication: Journal of Materials Science
publication_identifier:
  issn:
  - 0022-2461
  - 1573-4803
publication_status: published
publisher: Springer Science and Business Media LLC
quality_controlled: '1'
status: public
title: Evaluation and thermodynamic optimization of phase diagram of lithium niobate
  tantalate solid solutions
type: journal_article
user_id: '22501'
year: '2024'
...
---
_id: '49652'
abstract:
- lang: eng
  text: Broadband coherent anti-Stokes Raman scattering (BCARS) is a powerful spectroscopy
    method combining high signal intensity with spectral sensitivity, enabling rapid
    imaging of heterogeneous samples in biomedical research and, more recently, in
    crystalline materials. However, BCARS encounters spectral distortion due to a
    setup-dependent non-resonant background (NRB). This study assesses BCARS reproducibility
    through a round robin experiment using two distinct BCARS setups and crystalline
    materials with varying structural complexity, including diamond, 6H-SiC, KDP,
    and KTP. The analysis compares setup-specific NRB correction procedures, detected
    and NRB-removed spectra, and mode assignment. We determine the influence of BCARS
    setup parameters like pump wavelength, pulse width, and detection geometry and
    provide a practical guide for optimizing BCARS setups for solid-state applications.
article_number: '112'
article_type: original
author:
- first_name: Franz
  full_name: Hempel, Franz
  last_name: Hempel
- first_name: Federico
  full_name: Vernuccio, Federico
  last_name: Vernuccio
- first_name: Lukas
  full_name: König, Lukas
  last_name: König
- first_name: Robin
  full_name: Buschbeck, Robin
  last_name: Buschbeck
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Giulio
  full_name: Cerullo, Giulio
  last_name: Cerullo
- first_name: Dario
  full_name: Polli, Dario
  last_name: Polli
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: 'Hempel F, Vernuccio F, König L, et al. Comparing transmission- and epi-BCARS:
    a round robin on solid-state materials. <i>Applied Optics</i>. 2024;63(1). doi:<a
    href="https://doi.org/10.1364/ao.505374">10.1364/ao.505374</a>'
  apa: 'Hempel, F., Vernuccio, F., König, L., Buschbeck, R., Rüsing, M., Cerullo,
    G., Polli, D., &#38; Eng, L. M. (2024). Comparing transmission- and epi-BCARS:
    a round robin on solid-state materials. <i>Applied Optics</i>, <i>63</i>(1), Article
    112. <a href="https://doi.org/10.1364/ao.505374">https://doi.org/10.1364/ao.505374</a>'
  bibtex: '@article{Hempel_Vernuccio_König_Buschbeck_Rüsing_Cerullo_Polli_Eng_2024,
    title={Comparing transmission- and epi-BCARS: a round robin on solid-state materials},
    volume={63}, DOI={<a href="https://doi.org/10.1364/ao.505374">10.1364/ao.505374</a>},
    number={1112}, journal={Applied Optics}, publisher={Optica Publishing Group},
    author={Hempel, Franz and Vernuccio, Federico and König, Lukas and Buschbeck,
    Robin and Rüsing, Michael and Cerullo, Giulio and Polli, Dario and Eng, Lukas
    M.}, year={2024} }'
  chicago: 'Hempel, Franz, Federico Vernuccio, Lukas König, Robin Buschbeck, Michael
    Rüsing, Giulio Cerullo, Dario Polli, and Lukas M. Eng. “Comparing Transmission-
    and Epi-BCARS: A Round Robin on Solid-State Materials.” <i>Applied Optics</i>
    63, no. 1 (2024). <a href="https://doi.org/10.1364/ao.505374">https://doi.org/10.1364/ao.505374</a>.'
  ieee: 'F. Hempel <i>et al.</i>, “Comparing transmission- and epi-BCARS: a round
    robin on solid-state materials,” <i>Applied Optics</i>, vol. 63, no. 1, Art. no.
    112, 2024, doi: <a href="https://doi.org/10.1364/ao.505374">10.1364/ao.505374</a>.'
  mla: 'Hempel, Franz, et al. “Comparing Transmission- and Epi-BCARS: A Round Robin
    on Solid-State Materials.” <i>Applied Optics</i>, vol. 63, no. 1, 112, Optica
    Publishing Group, 2024, doi:<a href="https://doi.org/10.1364/ao.505374">10.1364/ao.505374</a>.'
  short: F. Hempel, F. Vernuccio, L. König, R. Buschbeck, M. Rüsing, G. Cerullo, D.
    Polli, L.M. Eng, Applied Optics 63 (2024).
date_created: 2023-12-15T07:32:38Z
date_updated: 2025-04-03T12:36:01Z
department:
- _id: '15'
- _id: '288'
- _id: '623'
doi: 10.1364/ao.505374
intvolume: '        63'
issue: '1'
keyword:
- Atomic and Molecular Physics
- and Optics
- Engineering (miscellaneous)
- Electrical and Electronic Engineering
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/pdf/2306.09701.pdf
oa: '1'
publication: Applied Optics
publication_identifier:
  issn:
  - 1559-128X
  - 2155-3165
publication_status: published
publisher: Optica Publishing Group
quality_controlled: '1'
related_material:
  link:
  - relation: confirmation
    url: https://arxiv.org/abs/2306.09701
status: public
title: 'Comparing transmission- and epi-BCARS: a round robin on solid-state materials'
type: journal_article
user_id: '22501'
volume: 63
year: '2024'
...
---
_id: '57028'
abstract:
- lang: eng
  text: <jats:p>Lithium niobate and lithium tantalate are among the most widespread
    materials for nonlinear, integrated photonics. Mixed crystals with arbitrary Nb–Ta
    ratios provide an additional degree of freedom to not only tune materials properties,
    such as the birefringence but also leverage the advantages of the singular compounds,
    for example, by combining the thermal stability of lithium tantalate with the
    larger nonlinear or piezoelectric constants of lithium niobate. Periodic poling
    allows to achieve phase-matching independent of waveguide geometry and is, therefore,
    one of the commonly used methods in integrated nonlinear optics. For mixed crystals,
    periodic poling has been challenging so far due to the lack of homogeneous, mono-domain
    crystals, which severely inhibit domain growth and nucleation. In this work, we
    investigate surface-near (&amp;lt;1μm depth) domain inversion on x-cut lithium
    niobate tantalate mixed crystals via electric field poling and lithographically
    structured electrodes. We find that naturally occurring head-to-head or tail-to-tail
    domain walls in the as-grown crystal inhibit domain inversion at a larger scale.
    However, periodic poling is possible if the gap size between the poling electrodes
    is of the same order of magnitude or smaller than the average size of naturally
    occurring domains. This work provides the basis for the nonlinear optical application
    of lithium niobate tantalate mixed crystals.</jats:p>
author:
- first_name: Laura
  full_name: Bollmers, Laura
  id: '61375'
  last_name: Bollmers
- first_name: Tobias
  full_name: Babai-Hemati, Tobias
  last_name: Babai-Hemati
- first_name: Boris
  full_name: Koppitz, Boris
  last_name: Koppitz
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Laura
  full_name: Padberg, Laura
  id: '40300'
  last_name: Padberg
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
citation:
  ama: Bollmers L, Babai-Hemati T, Koppitz B, et al. Surface-near domain engineering
    in multi-domain x-cut lithium niobate tantalate mixed crystals. <i>Applied Physics
    Letters</i>. 2024;125(15). doi:<a href="https://doi.org/10.1063/5.0210972">10.1063/5.0210972</a>
  apa: Bollmers, L., Babai-Hemati, T., Koppitz, B., Eigner, C., Padberg, L., Rüsing,
    M., Eng, L. M., &#38; Silberhorn, C. (2024). Surface-near domain engineering in
    multi-domain x-cut lithium niobate tantalate mixed crystals. <i>Applied Physics
    Letters</i>, <i>125</i>(15). <a href="https://doi.org/10.1063/5.0210972">https://doi.org/10.1063/5.0210972</a>
  bibtex: '@article{Bollmers_Babai-Hemati_Koppitz_Eigner_Padberg_Rüsing_Eng_Silberhorn_2024,
    title={Surface-near domain engineering in multi-domain x-cut lithium niobate tantalate
    mixed crystals}, volume={125}, DOI={<a href="https://doi.org/10.1063/5.0210972">10.1063/5.0210972</a>},
    number={15}, journal={Applied Physics Letters}, publisher={AIP Publishing}, author={Bollmers,
    Laura and Babai-Hemati, Tobias and Koppitz, Boris and Eigner, Christof and Padberg,
    Laura and Rüsing, Michael and Eng, Lukas M. and Silberhorn, Christine}, year={2024}
    }'
  chicago: Bollmers, Laura, Tobias Babai-Hemati, Boris Koppitz, Christof Eigner, Laura
    Padberg, Michael Rüsing, Lukas M. Eng, and Christine Silberhorn. “Surface-near
    Domain Engineering in Multi-Domain x-Cut Lithium Niobate Tantalate Mixed Crystals.”
    <i>Applied Physics Letters</i> 125, no. 15 (2024). <a href="https://doi.org/10.1063/5.0210972">https://doi.org/10.1063/5.0210972</a>.
  ieee: 'L. Bollmers <i>et al.</i>, “Surface-near domain engineering in multi-domain
    x-cut lithium niobate tantalate mixed crystals,” <i>Applied Physics Letters</i>,
    vol. 125, no. 15, 2024, doi: <a href="https://doi.org/10.1063/5.0210972">10.1063/5.0210972</a>.'
  mla: Bollmers, Laura, et al. “Surface-near Domain Engineering in Multi-Domain x-Cut
    Lithium Niobate Tantalate Mixed Crystals.” <i>Applied Physics Letters</i>, vol.
    125, no. 15, AIP Publishing, 2024, doi:<a href="https://doi.org/10.1063/5.0210972">10.1063/5.0210972</a>.
  short: L. Bollmers, T. Babai-Hemati, B. Koppitz, C. Eigner, L. Padberg, M. Rüsing,
    L.M. Eng, C. Silberhorn, Applied Physics Letters 125 (2024).
date_created: 2024-11-13T08:06:59Z
date_updated: 2024-11-15T09:15:08Z
department:
- _id: '15'
- _id: '623'
- _id: '230'
- _id: '288'
doi: 10.1063/5.0210972
intvolume: '       125'
issue: '15'
language:
- iso: eng
project:
- _id: '168'
  grant_number: '231447078'
  name: 'TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften
    von Lithiumniobat (B07*)'
publication: Applied Physics Letters
publication_identifier:
  issn:
  - 0003-6951
  - 1077-3118
publication_status: published
publisher: AIP Publishing
status: public
title: Surface-near domain engineering in multi-domain x-cut lithium niobate tantalate
  mixed crystals
type: journal_article
user_id: '61375'
volume: 125
year: '2024'
...
---
_id: '59269'
abstract:
- lang: eng
  text: Ferroelectric materials play a crucial role in a broad range of technologies
    due to their unique properties that are deeply connected to the pattern and behavior
    of their ferroelectric (FE) domains. Chief among them, barium titanate (BaTiO3;
    BTO) sees widespread applications such as in electronics but equally is a ferroelectric
    model system for fundamental research, e.g., to study the interplay of such FE
    domains, the domain walls (DWs), and their macroscopic properties, owed to BTO’s
    multiple and experimentally accessible phase transitions. Here, we employ Second
    Harmonic Generation Microscopy (SHGM) to in situ investigate the cubic-to-tetragonal
    (at ∼126°C) and the tetragonal-to-orthorhombic (at ∼5°C) phase transition in single-crystalline
    BTO via three-dimensional (3D) DW mapping. We demonstrate that SHGM imaging provides
    the direct visualization of FE domain switching as well as the domain dynamics
    in 3D, shedding light on the interplay of the domain structure and phase transition.
    These results allow us to extract the different transition temperatures locally,
    to unveil the hysteresis behavior, and to determine the type of phase transition
    at play (first/second order) from the recorded SHGM data. The capabilities of
    SHGM in uncovering these crucial phenomena can easily be applied to other ferroelectrics
    to provide new possibilities for in situ engineering of advanced ferroic devices.
article_number: '154102'
article_type: original
author:
- first_name: Benjamin
  full_name: Kirbus, Benjamin
  last_name: Kirbus
- first_name: Samuel D.
  full_name: Seddon, Samuel D.
  last_name: Seddon
- first_name: Iuliia
  full_name: Kiseleva, Iuliia
  last_name: Kiseleva
- first_name: Elke
  full_name: Beyreuther, Elke
  last_name: Beyreuther
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: Kirbus B, Seddon SD, Kiseleva I, Beyreuther E, Rüsing M, Eng LM. Probing ferroelectric
    phase transitions in barium titanate single crystals via in-situ second harmonic
    generation microscopy. <i>Journal of Applied Physics</i>. 2024;136(15). doi:<a
    href="https://doi.org/10.1063/5.0237769">10.1063/5.0237769</a>
  apa: Kirbus, B., Seddon, S. D., Kiseleva, I., Beyreuther, E., Rüsing, M., &#38;
    Eng, L. M. (2024). Probing ferroelectric phase transitions in barium titanate
    single crystals via in-situ second harmonic generation microscopy. <i>Journal
    of Applied Physics</i>, <i>136</i>(15), Article 154102. <a href="https://doi.org/10.1063/5.0237769">https://doi.org/10.1063/5.0237769</a>
  bibtex: '@article{Kirbus_Seddon_Kiseleva_Beyreuther_Rüsing_Eng_2024, title={Probing
    ferroelectric phase transitions in barium titanate single crystals via in-situ
    second harmonic generation microscopy}, volume={136}, DOI={<a href="https://doi.org/10.1063/5.0237769">10.1063/5.0237769</a>},
    number={15154102}, journal={Journal of Applied Physics}, publisher={AIP Publishing},
    author={Kirbus, Benjamin and Seddon, Samuel D. and Kiseleva, Iuliia and Beyreuther,
    Elke and Rüsing, Michael and Eng, Lukas M.}, year={2024} }'
  chicago: Kirbus, Benjamin, Samuel D. Seddon, Iuliia Kiseleva, Elke Beyreuther, Michael
    Rüsing, and Lukas M. Eng. “Probing Ferroelectric Phase Transitions in Barium Titanate
    Single Crystals via In-Situ Second Harmonic Generation Microscopy.” <i>Journal
    of Applied Physics</i> 136, no. 15 (2024). <a href="https://doi.org/10.1063/5.0237769">https://doi.org/10.1063/5.0237769</a>.
  ieee: 'B. Kirbus, S. D. Seddon, I. Kiseleva, E. Beyreuther, M. Rüsing, and L. M.
    Eng, “Probing ferroelectric phase transitions in barium titanate single crystals
    via in-situ second harmonic generation microscopy,” <i>Journal of Applied Physics</i>,
    vol. 136, no. 15, Art. no. 154102, 2024, doi: <a href="https://doi.org/10.1063/5.0237769">10.1063/5.0237769</a>.'
  mla: Kirbus, Benjamin, et al. “Probing Ferroelectric Phase Transitions in Barium
    Titanate Single Crystals via In-Situ Second Harmonic Generation Microscopy.” <i>Journal
    of Applied Physics</i>, vol. 136, no. 15, 154102, AIP Publishing, 2024, doi:<a
    href="https://doi.org/10.1063/5.0237769">10.1063/5.0237769</a>.
  short: B. Kirbus, S.D. Seddon, I. Kiseleva, E. Beyreuther, M. Rüsing, L.M. Eng,
    Journal of Applied Physics 136 (2024).
date_created: 2025-04-02T15:57:11Z
date_updated: 2025-04-02T15:59:55Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1063/5.0237769
intvolume: '       136'
issue: '15'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: ' https://doi.org/10.1063/5.0237769'
oa: '1'
publication: Journal of Applied Physics
publication_identifier:
  issn:
  - 0021-8979
  - 1089-7550
publication_status: published
publisher: AIP Publishing
quality_controlled: '1'
status: public
title: Probing ferroelectric phase transitions in barium titanate single crystals
  via in-situ second harmonic generation microscopy
type: journal_article
user_id: '22501'
volume: 136
year: '2024'
...
---
_id: '59271'
abstract:
- lang: eng
  text: Lithium niobate (LNO) and lithium tantalate (LTO) see widespread use in fundamental
    research and commercial technologies reaching from electronics over classical
    optics to integrated quantum communication. The mixed crystal system lithium niobate
    tantalate (LNT) allows for the dedicate engineering of material properties by
    combining the advantages of the two parental materials LNO and LTO. Vibrational
    spectroscopies such as Raman spectroscopy or (Fourier transform) infrared (IR)
    spectroscopy are vital techniques to provide detailed insight into the material
    properties, which is central to the analysis and optimization of devices. This
    work presents a joint experimental–theoretical approach allowing to unambiguously
    assign the spectral features in the LNT material family through both Raman and
    IR spectroscopy, as well as providing an in‐depth explanation for the observed
    scattering efficiencies based on first‐principles calculations. The phononic contribution
    to the static dielectric tensor is calculated from the experimental and theoretical
    data using the generalized Lyddane–Sachs–Teller relation and compared with the
    results of the first‐principles calculations.
author:
- first_name: Felix
  full_name: Bernhardt, Felix
  last_name: Bernhardt
- first_name: Soham
  full_name: Gharat, Soham
  last_name: Gharat
- first_name: Alexander
  full_name: Kapp, Alexander
  last_name: Kapp
- first_name: Florian
  full_name: Pfeiffer, Florian
  last_name: Pfeiffer
- first_name: Robin
  full_name: Buschbeck, Robin
  last_name: Buschbeck
- first_name: Franz
  full_name: Hempel, Franz
  last_name: Hempel
- first_name: Oleksiy
  full_name: Pashkin, Oleksiy
  last_name: Pashkin
- first_name: Susanne C.
  full_name: Kehr, Susanne C.
  last_name: Kehr
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
citation:
  ama: 'Bernhardt F, Gharat S, Kapp A, et al. Lattice Dynamics of LiNb(1–x)Ta(x)O3
    Solid Solutions: Theory and Experiment. <i>physica status solidi (a)</i>. 2024;222(1):2300968.
    doi:<a href="https://doi.org/10.1002/pssa.202300968">10.1002/pssa.202300968</a>'
  apa: 'Bernhardt, F., Gharat, S., Kapp, A., Pfeiffer, F., Buschbeck, R., Hempel,
    F., Pashkin, O., Kehr, S. C., Rüsing, M., Sanna, S., &#38; Eng, L. M. (2024).
    Lattice Dynamics of LiNb(1–x)Ta(x)O3 Solid Solutions: Theory and Experiment. <i>Physica
    Status Solidi (a)</i>, <i>222</i>(1), 2300968. <a href="https://doi.org/10.1002/pssa.202300968">https://doi.org/10.1002/pssa.202300968</a>'
  bibtex: '@article{Bernhardt_Gharat_Kapp_Pfeiffer_Buschbeck_Hempel_Pashkin_Kehr_Rüsing_Sanna_et
    al._2024, title={Lattice Dynamics of LiNb(1–x)Ta(x)O3 Solid Solutions: Theory
    and Experiment}, volume={222}, DOI={<a href="https://doi.org/10.1002/pssa.202300968">10.1002/pssa.202300968</a>},
    number={1}, journal={physica status solidi (a)}, publisher={Wiley}, author={Bernhardt,
    Felix and Gharat, Soham and Kapp, Alexander and Pfeiffer, Florian and Buschbeck,
    Robin and Hempel, Franz and Pashkin, Oleksiy and Kehr, Susanne C. and Rüsing,
    Michael and Sanna, Simone and et al.}, year={2024}, pages={2300968} }'
  chicago: 'Bernhardt, Felix, Soham Gharat, Alexander Kapp, Florian Pfeiffer, Robin
    Buschbeck, Franz Hempel, Oleksiy Pashkin, et al. “Lattice Dynamics of LiNb(1–x)Ta(x)O3
    Solid Solutions: Theory and Experiment.” <i>Physica Status Solidi (a)</i> 222,
    no. 1 (2024): 2300968. <a href="https://doi.org/10.1002/pssa.202300968">https://doi.org/10.1002/pssa.202300968</a>.'
  ieee: 'F. Bernhardt <i>et al.</i>, “Lattice Dynamics of LiNb(1–x)Ta(x)O3 Solid Solutions:
    Theory and Experiment,” <i>physica status solidi (a)</i>, vol. 222, no. 1, p.
    2300968, 2024, doi: <a href="https://doi.org/10.1002/pssa.202300968">10.1002/pssa.202300968</a>.'
  mla: 'Bernhardt, Felix, et al. “Lattice Dynamics of LiNb(1–x)Ta(x)O3 Solid Solutions:
    Theory and Experiment.” <i>Physica Status Solidi (a)</i>, vol. 222, no. 1, Wiley,
    2024, p. 2300968, doi:<a href="https://doi.org/10.1002/pssa.202300968">10.1002/pssa.202300968</a>.'
  short: F. Bernhardt, S. Gharat, A. Kapp, F. Pfeiffer, R. Buschbeck, F. Hempel, O.
    Pashkin, S.C. Kehr, M. Rüsing, S. Sanna, L.M. Eng, Physica Status Solidi (a) 222
    (2024) 2300968.
date_created: 2025-04-02T16:04:58Z
date_updated: 2025-04-02T16:07:19Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1002/pssa.202300968
intvolume: '       222'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1002/pssa.202300968
oa: '1'
page: '2300968'
publication: physica status solidi (a)
publication_identifier:
  issn:
  - 1862-6300
  - 1862-6319
publication_status: published
publisher: Wiley
status: public
title: 'Lattice Dynamics of LiNb(1–x)Ta(x)O3 Solid Solutions: Theory and Experiment'
type: journal_article
user_id: '22501'
volume: 222
year: '2024'
...
---
_id: '59270'
abstract:
- lang: eng
  text: Lithium niobate tantalate (LiNb1−xTaxO3, LNT) solid solutions offer exciting
    new possibilities for applications ranging from optics, piezotronics, and electronics
    beyond the capabilities of the widely used singular compounds of lithium niobate
    (LiNbO3, LN) or lithium tantalate (LiTaO3, LT). Crystal growth of homogeneous
    LNT single crystals by the Czochralski method is still challenging. One key aspect
    of homogeneous growth is the accurate knowledge of thermal conductivity through
    the crystal boule during the growth, which is central to control the crystal growth.
    Therefore, the temperature dependent thermal conductivity of pure LN, LT, and
    LNT solid solutions, as well as of selected doped LN and LT crystals (Mg, Zn)
    was investigated across the temperature range from 300 to 1300 K. The results
    that span across the whole composition range can directly be applied for optimizing
    growth conditions of both LNT solid solutions as well as doped and undoped LN
    and LT crystals.
article_number: '176549'
article_type: original
author:
- first_name: Umar
  full_name: Bashir, Umar
  last_name: Bashir
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Detlef
  full_name: Klimm, Detlef
  last_name: Klimm
- first_name: Roberts
  full_name: Blukis, Roberts
  last_name: Blukis
- first_name: Boris
  full_name: Koppitz, Boris
  last_name: Koppitz
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
- first_name: Matthias
  full_name: Bickermann, Matthias
  last_name: Bickermann
- first_name: Steffen
  full_name: Ganschow, Steffen
  last_name: Ganschow
citation:
  ama: Bashir U, Rüsing M, Klimm D, et al. Thermal conductivity in solid solutions
    of lithium niobate tantalate single crystals from 300 K up to 1300 K. <i>Journal
    of Alloys and Compounds</i>. 2024;1008. doi:<a href="https://doi.org/10.1016/j.jallcom.2024.176549">10.1016/j.jallcom.2024.176549</a>
  apa: Bashir, U., Rüsing, M., Klimm, D., Blukis, R., Koppitz, B., Eng, L. M., Bickermann,
    M., &#38; Ganschow, S. (2024). Thermal conductivity in solid solutions of lithium
    niobate tantalate single crystals from 300 K up to 1300 K. <i>Journal of Alloys
    and Compounds</i>, <i>1008</i>, Article 176549. <a href="https://doi.org/10.1016/j.jallcom.2024.176549">https://doi.org/10.1016/j.jallcom.2024.176549</a>
  bibtex: '@article{Bashir_Rüsing_Klimm_Blukis_Koppitz_Eng_Bickermann_Ganschow_2024,
    title={Thermal conductivity in solid solutions of lithium niobate tantalate single
    crystals from 300 K up to 1300 K}, volume={1008}, DOI={<a href="https://doi.org/10.1016/j.jallcom.2024.176549">10.1016/j.jallcom.2024.176549</a>},
    number={176549}, journal={Journal of Alloys and Compounds}, publisher={Elsevier
    BV}, author={Bashir, Umar and Rüsing, Michael and Klimm, Detlef and Blukis, Roberts
    and Koppitz, Boris and Eng, Lukas M. and Bickermann, Matthias and Ganschow, Steffen},
    year={2024} }'
  chicago: Bashir, Umar, Michael Rüsing, Detlef Klimm, Roberts Blukis, Boris Koppitz,
    Lukas M. Eng, Matthias Bickermann, and Steffen Ganschow. “Thermal Conductivity
    in Solid Solutions of Lithium Niobate Tantalate Single Crystals from 300 K up
    to 1300 K.” <i>Journal of Alloys and Compounds</i> 1008 (2024). <a href="https://doi.org/10.1016/j.jallcom.2024.176549">https://doi.org/10.1016/j.jallcom.2024.176549</a>.
  ieee: 'U. Bashir <i>et al.</i>, “Thermal conductivity in solid solutions of lithium
    niobate tantalate single crystals from 300 K up to 1300 K,” <i>Journal of Alloys
    and Compounds</i>, vol. 1008, Art. no. 176549, 2024, doi: <a href="https://doi.org/10.1016/j.jallcom.2024.176549">10.1016/j.jallcom.2024.176549</a>.'
  mla: Bashir, Umar, et al. “Thermal Conductivity in Solid Solutions of Lithium Niobate
    Tantalate Single Crystals from 300 K up to 1300 K.” <i>Journal of Alloys and Compounds</i>,
    vol. 1008, 176549, Elsevier BV, 2024, doi:<a href="https://doi.org/10.1016/j.jallcom.2024.176549">10.1016/j.jallcom.2024.176549</a>.
  short: U. Bashir, M. Rüsing, D. Klimm, R. Blukis, B. Koppitz, L.M. Eng, M. Bickermann,
    S. Ganschow, Journal of Alloys and Compounds 1008 (2024).
date_created: 2025-04-02T16:00:56Z
date_updated: 2025-04-02T16:02:26Z
department:
- _id: '15'
- _id: '288'
- _id: '623'
doi: 10.1016/j.jallcom.2024.176549
intvolume: '      1008'
language:
- iso: eng
publication: Journal of Alloys and Compounds
publication_identifier:
  issn:
  - 0925-8388
publication_status: published
publisher: Elsevier BV
quality_controlled: '1'
status: public
title: Thermal conductivity in solid solutions of lithium niobate tantalate single
  crystals from 300 K up to 1300 K
type: journal_article
user_id: '22501'
volume: 1008
year: '2024'
...
---
_id: '59272'
abstract:
- lang: eng
  text: 'Ferroelectrics such as LiNbO3 (LN) are wide-band-gap insulators that may
    show a high local electric conductivity at the domain walls (DWs). The latter
    are interfaces separating regions of noncollinear polarization, which can be manipulated
    to build integrated nanoelectronic elements. In the present work, we model different
    DW types in LN from first principles. Our models reveal the DW morphology and
    shed light on their electronic properties: A strong band bending is predicted
    for charged DWs, leading to local metallicity. Defect trapping at the DW may further
    enhance the electric conductivity.'
article_number: L042015
author:
- first_name: Leonard M.
  full_name: Verhoff, Leonard M.
  last_name: Verhoff
- first_name: Mike N.
  full_name: Pionteck, Mike N.
  last_name: Pionteck
- first_name: Michael
  full_name: Rüsing, Michael
  id: '22501'
  last_name: Rüsing
  orcid: 0000-0003-4682-4577
- first_name: Holger
  full_name: Fritze, Holger
  last_name: Fritze
- first_name: Lukas M.
  full_name: Eng, Lukas M.
  last_name: Eng
- first_name: Simone
  full_name: Sanna, Simone
  last_name: Sanna
citation:
  ama: 'Verhoff LM, Pionteck MN, Rüsing M, Fritze H, Eng LM, Sanna S. Two-dimensional
    electronic conductivity in insulating ferroelectrics: Peculiar properties of domain
    walls. <i>Physical Review Research</i>. 2024;6(4). doi:<a href="https://doi.org/10.1103/physrevresearch.6.l042015">10.1103/physrevresearch.6.l042015</a>'
  apa: 'Verhoff, L. M., Pionteck, M. N., Rüsing, M., Fritze, H., Eng, L. M., &#38;
    Sanna, S. (2024). Two-dimensional electronic conductivity in insulating ferroelectrics:
    Peculiar properties of domain walls. <i>Physical Review Research</i>, <i>6</i>(4),
    Article L042015. <a href="https://doi.org/10.1103/physrevresearch.6.l042015">https://doi.org/10.1103/physrevresearch.6.l042015</a>'
  bibtex: '@article{Verhoff_Pionteck_Rüsing_Fritze_Eng_Sanna_2024, title={Two-dimensional
    electronic conductivity in insulating ferroelectrics: Peculiar properties of domain
    walls}, volume={6}, DOI={<a href="https://doi.org/10.1103/physrevresearch.6.l042015">10.1103/physrevresearch.6.l042015</a>},
    number={4L042015}, journal={Physical Review Research}, publisher={American Physical
    Society (APS)}, author={Verhoff, Leonard M. and Pionteck, Mike N. and Rüsing,
    Michael and Fritze, Holger and Eng, Lukas M. and Sanna, Simone}, year={2024} }'
  chicago: 'Verhoff, Leonard M., Mike N. Pionteck, Michael Rüsing, Holger Fritze,
    Lukas M. Eng, and Simone Sanna. “Two-Dimensional Electronic Conductivity in Insulating
    Ferroelectrics: Peculiar Properties of Domain Walls.” <i>Physical Review Research</i>
    6, no. 4 (2024). <a href="https://doi.org/10.1103/physrevresearch.6.l042015">https://doi.org/10.1103/physrevresearch.6.l042015</a>.'
  ieee: 'L. M. Verhoff, M. N. Pionteck, M. Rüsing, H. Fritze, L. M. Eng, and S. Sanna,
    “Two-dimensional electronic conductivity in insulating ferroelectrics: Peculiar
    properties of domain walls,” <i>Physical Review Research</i>, vol. 6, no. 4, Art.
    no. L042015, 2024, doi: <a href="https://doi.org/10.1103/physrevresearch.6.l042015">10.1103/physrevresearch.6.l042015</a>.'
  mla: 'Verhoff, Leonard M., et al. “Two-Dimensional Electronic Conductivity in Insulating
    Ferroelectrics: Peculiar Properties of Domain Walls.” <i>Physical Review Research</i>,
    vol. 6, no. 4, L042015, American Physical Society (APS), 2024, doi:<a href="https://doi.org/10.1103/physrevresearch.6.l042015">10.1103/physrevresearch.6.l042015</a>.'
  short: L.M. Verhoff, M.N. Pionteck, M. Rüsing, H. Fritze, L.M. Eng, S. Sanna, Physical
    Review Research 6 (2024).
date_created: 2025-04-02T16:08:55Z
date_updated: 2025-04-02T16:10:59Z
department:
- _id: '623'
- _id: '288'
- _id: '15'
doi: 10.1103/physrevresearch.6.l042015
intvolume: '         6'
issue: '4'
language:
- iso: eng
main_file_link:
- url: https://jlupub.ub.uni-giessen.de/server/api/core/bitstreams/fb2b09e6-c0f8-4209-99a1-79fc81d9b1f9/content
publication: Physical Review Research
publication_identifier:
  issn:
  - 2643-1564
publication_status: published
publisher: American Physical Society (APS)
status: public
title: 'Two-dimensional electronic conductivity in insulating ferroelectrics: Peculiar
  properties of domain walls'
type: journal_article
user_id: '22501'
volume: 6
year: '2024'
...
